87 C/K20 3+3 Long box - Body questions

[Cervantes]

Hi!
Just got an old Canadian Highway Services 3+3 longbox this winter to fix up and make my work truck.

I'm working on the body, and I had a few questions about that.

- I'm looking to replace the doors... the winner before me screwed in some towing mirrors and didn't prime the screw holes, so now there's dinner-plate sized patches that are rusted right through. I found what seems to be a mid-80's Suburban that has doors in pretty good shape, they seem the right size, only difference is they're heavier. Not sure on the year, the body looks the same as mine, except the front turn signals are vertical stripes instead of horizontal. Can I expect them to fit?

- The bench seat is worn out and I'm going to replace the fronts with buckets when I can find some nice ones. I know there's some threads about it, but if anyone has any extra hints about putting in the rails, that'd be cool

- The back window is the non-opening type (it is a no-frills gov't truck, of course), I'd like to replace it with one of the sliders I saw at the yard. Is it just an H-channel rubber gasket holding it in that I can lever up and off, or do I have to do something special to get it out in one piece?

- The gas fill tube drives me nuts already, and it's been one fill! Has anyone modded theirs to sit higher up on the fender? I'm presuming that's the best way to not have to fight with the fill nozzel. Anyone have any hints on gettin er fixed up?

Thanks!
C