I believe that the moniker Weaver was adopted when the company ventured into injection molded plastic models in O scale around the early 1980s. At that time, both Atlas and AHM had been unsuccessful at marketing plastic RTR O scale models and the outlook for getting state-of-the art models in O scale was bleak. Weaver's entry into the genre was a very welcome addition. I remember hearing from Bob Weaver at a clinic that he gave at the 1985 O Scale National that his choice of an open coal hopper as his first offering was very fortuitous. This was because modelers would run solid trains of these hoppers; that was good for sales. Bob also told us that every time that he came out with a new freight car he "bought a house" - comparing the cost of having dies made to the (then) cost of a new house. His second choice of a car design, the modern tank car, nearly put him out of business because it dd not sell well at all.
At that '85 convention he was showing off samples of his newest car, the PS-2 covered hopper. As a gag, he had painted one up in brass-colored paint and was putting on some of the dealers that he was making brass cars at $20 each. This was back in the day when the hobby was lousy with guys who were treating brass models as objet d'art and thinking that they were going to retire by cashing in their brass collections for big bucks. Weaver, at the vanguard of the wave of detailed and inexpensive plastic models that would follow, put an end to those ambitions; and I, for one, think that the hobby is better for it.
Weaver's early offerings were only available in kit form, less trucks and couplers. They were very analogous to Athearn "blue box", shake-the-box kits. For example, the hopper had a one-piece body with all of the grabs cast on, a separate under frame, a brake wheel, brake reservoir/triple valve cluster and two braces for the hopper slope sheets - 6 parts in all. The kits were originally set-up for 2-rail trucks (Athearn being the logical choice at the time) and Kadee couplers. Eventually, Weaver realized the size of the 3-rail market and developed a 3 rail truck with a truck-mounted coupler. At a later O scale convention, Bob Weaver opined that the 3 rail market was about three times the size of the 2-rail market. Weaver's lack of fine detail was a natural fit for the 3-rail market of that day with it's more casual operations. Eventually Weaver offered their own trucks and couplers in 2 and 3 rail, in plastic and diecast; the latter a 'must' for the 3-rail aficionado. RTR cars are an imperative for the 3-rail crowd and Weaver eventually offered those too. Soon thereafter, the kit versions were withdrawn from the market.
Weavers early models, and most of their models to the very end, were made in the USA. Weaver developed their own in-house pad-printing process to decorate the models. And Weaver built models the old fashioned way (probably to it's detriment) by speculating on which models would sell and in what quantity. As far as I know, they never adopted the build-to-order business model that is now industry standard. Weaver would also do special runs and, because they had most processes in-house, they could do very short runs. In fact, many of the Weaver boxcars that I have are special runs for dealers, historical societies, conventions, etc.
The next big breakthrough for Weaver came when they offered RTR plastic diesels, beginning with the Alco RS-3 (RSD-4/5 later, too) and the Alco FA-2/FB-2. Bowing to time-honored O Scale tradition, these were powered by a Pittman motor and all-axle geared drive. The GP38-2 followed and these were regularly cataloged items.
Many of these car types (e.g. RoadRailers, 57' Reefers, High-Side Hoppers) have not been done before or since in O scale. Road names for each of these changed from year to year and counting all of the variations would lead to thousands, if not 10,000 or more distinct products.
With the advent of building models in China, Weaver eventually branched out into passenger cars, offering smooth and fluted-side streamline cars in many different road names as well as the unique offerings like the Pullman-Bradley coaches and a Milwaukee Hiawatha with beavertail observation. The wartime Troop Sleeper, Kitchen Cars and Coaches were offered in both passenger and the postwar express car configurations.
But the biggest bonus in offshore manufacturing occurred in locomotive production. Plastic versions of the U25B, RS-11/12, E8, SD40-2, Baldwin Sharknose and the VO-1000 (and probably some that I've forgotten) were offered from time to time. These locomotives utilized the oft-decried "China Drive". The dual motor drive was what was offered by the Chinese builders and a requirement woven into the culture of the 3-rail community. At about this time, the domestically produced diesels were transitioned to the China drive as well (which made me question their Made-In-USA advertising). I suspect that some of these locos were piggybacked onto builds by Lionel, K-Line and MTH, all larger builders; and that the die work was subsidized by the Chinese manufacturers.
Another windfall from China production was in diecast steam locos. Weaver produced a Pacific (I have one and love it), a Consolidation and a 0-6-0, at least. Again, I believe that all of these were piggybacked on the production runs of Weaver's larger rivals.
Weaver did not eschew building in brass. They offered many, many brass steamers, biased towards larger passenger steam, streamlined steam and, the mandatory PRR K4s and T1 and NYC Hudson notwithstanding, representing the less frequently modeled roads (GN, MILW, NH, NKP, CN, CP, LV, etc.). In addition to brass steamers, brass cabooses, electrics and even brass structures were imported.
For all of the good things that Weaver accomplished, the current owner is hanging it up and retiring and, apparently, there are no offers for his business. While this is sad, it is not surprising. Realistically, while Weaver was a godsend in the '80s, they did not keep up with the times. Their detail is not up to current standards, nor do they offer railroad-specific details.
I'm speculating, but the MLW horizontal rib boxcar, B&O wagontop boxcar and the PRR H30 covered hopper were probably Weaver's attempt to produce cars that were more up to date. I heard rumors that they were unhappy with all of these cars and swore not to do it again. We modelers did not help; people nitpicked the paint schemes on all 3; and the less desirable schemes are still unsold after 4 years.
Finally, Weaver's business model of building models on speculation of which models should be run and what road names will sell is probably no longer viable. I hate to admit it, but the other manufacturer's build-to-order business model is likely correct for the times.
There were clues to Weaver's demise that you can see in hindsight. The last catalog (Fall 2014) did not list any of the diesels (requiring mechanisms from China). The only rolling stock listed were a subset of the ones made in the USA; presumably because Weaver owns the molds and can decorate them in-house. The cars that Weaver imported, and probably had to bring in by the container load, were nowhere to be found.
I hope that some of Weaver's molds will be picked up by Atlas. They could fit into their Trainman or Industrial Rail lines. Weaver's 3 bay hoppers (ribbed and offset), 9 panel hoppers and high side hoppers would really fill out Atlas' hopper offerings. If the molds were upgraded, run infrequently, and built to order these could carry their own weight; especially if the molds are obtained at fire sale prices. Ditto the 57' reefers; and maybe the flats. But for the 2 bay hoppers, box cars and reefers, tanks, and covered hoppers, Atlas already has better offerings.
In recent years I have vacillated on whether I should use the several score unassembled Weaver kits and assembled cars that I have. I had been in favor of keeping the boxcars, 3 bay hoppers and PS-2 covered hoppers and disposing of the 2-bay hoppers as being too crude. My last swing on this topic before the announcement was to keep all of the Weaver cars as they are relatively immune to handling and so can be taken on and off of the layout for variation in consists. The demise of Weaver only reinforces this decision.
Weaver models are still readily available on the secondary market, although you may have to do some painting to get your preferred road name. They will live on much as the '70s Atlas cars are still found on almost everyone's layouts.
I will miss Weaver; as I lamented the loss of Weaver's and others' kits. Weaver cars were rugged and were inexpensive enough to fill out your layout. But the option of having in-stock models, available when you are ready to order, will be the greatest loss of all.