On the SR5 aluminum wheels:
I'm pretty sure that all the Toyota wheels of that style have the exact same dimensions. They were offered on Trucks, T100s, IFS 1st and 2nd-gen 4runners, and FJ80s but they have too much backspacing to fit on 1985 and earlier Trucks and 4runners without spacers.
The 15x6 6-spoke steel wheels on Rotbox's truck (BTW, that's quite a feat to pull 37's onto 15x6s!) came on 1985 and earlier Trucks and 4runners as well as FJ60 and FJ62 Land Cruisers. They do have the correct backspacing to fit on solid axle Trucks and 4runners.
Indhark--mine's not an FWC. It's a Four Seasons (defunct, Colorado company, wooden construction) from 1988.
I love the earlier trucks. I like to look at newer trucks but it would be really tough to get myself to go newer--they just don't have what the earlier ones do.