fitting a smaller range
Shop around, if you can wait a bit - folks remodel and put them on craigslist somewhat regularly; or look more seriously at having the range you have repaired, if you have not (unclear how far you went down that road before declaring it dead) as it may cost less than anything else, even if it feels expensive. For most ranges, a good rebuilder can not only restore function, but also remove most of the "very used" look and feel. Ask to see examples of their work. You may need to look to a larger city you'd have to drive to in order  to find one, but appliance rebuilders are out there.

The problem with "adding storage" is that you are only looking at 4" less width, so by the time you put in a couple of cabinet sides you've got a space that can be handy for cookie sheets, but not much else - if you don't extend the countertop over it, it looks weird (and collects crud, spills, grease etc), and if you do, it still looks weird, unless you can actually get a full-on match (possible with some stone and solid surface materials, and a good contractor - but it may cost you enough to make the replacement stove at 40" look like a better way to spend your money.)