Absolutely, a good modeler is likely to be a good scavenger/scrounger, as shown by the responses. In fact, for us old-timers (Hammer, I respectfully include you) before anyone had ever heard the words "aftermarket" or "photo-etch", we had a term called "creative gizmology" (cf Shep Paine's books and articles). If you had an old piece of electronics, for example, you didn't throw it out, until you had stripped it of anything that might be used, certainly the wire. When I was a kid, I made spaceships out of the guts of old vacuum tubes.
As for cross-pollination between modeling hobbies, sure, you can find a lot of useful things in shops or catalogs aimed at model railroaders, or ship builders--a ton of small brass or wooden bits, for example, or decals, paints, molded plastic stock, ready-made electronics for making moving displays, to say nothing of the knowledge that old-timer model railroaders have.
In short, keep your eyes and ears open, you never know where something useful will turn up next.
Regards,
Brad