What did Lego set instruction manuals look like in the past?
The earliest LEGO sets did not have any kind of instruction manuals, since they were sold as sets of building blocks, without any specific models in mind.
Exmaple: Set #7002, Automatic Binding Bricks from 1949

In 1955, the first sets have arrived that were intended to be built as some specific model, like 1237-2: Service Station

I can't find any instructions for this one, but two years later the 1306: VW Garage had four steps on the inside of the box to aid in building:

A newer example from 1965 is the 320: Airplane set, which had a four pages long instruction manual of which two pages were inspirational images of alternative builds:


Jumping another ten years ahead to 1975, we see that the instruction manual for 253-2: Helicopter and Pilot has a whopping 3 pages dedicated to the main build:



Further 10 years into the future, a representative set would be 107-2: Mail Truck, whose assembly instructions do not differ significantly, just get a bit more detailed:

By 1990 we get to the most complex style yet, with stepwise part lists and insets in insets for the Technic and the similarly complex Model Team lines, like for example the instructions for 5590: Whirl and Wheel Super Truck:

From there the style is basically unchanged, and the trend is to use fewer pieces per step, sometimes &quot;sacrificing&quot; a whole step just to show the model being flipped or rotated.