I'd love to see Bachmann make Rahway Valley RR #16 and #17 GE 70 tonners in their awesome little N scale models. They had what I believe were GE factory-standard paint schemes. Anyone else?
B-mann sells a red 70-Tonner. so you could buy the red one, paint over the stripes that are not there, then look on some of the decal sheets and see if you can get the striping that you do want. The lettering might be more difficult.
B-mann does not sell a green 70-Tonner, so you would have to strip something for that one and re-paint.
It is not difficult to get the shell off the power chassis. The hard parts are:
1. Getting out the glazing. Bachpersonn uses some super stick glue to keep the glazing in the cab, When you try to take it out, is discombobulates. You can use Microscale's Mikro Kristall Kleer to re-do the windows.
2. Getting the railing to go back once you get them out.
The easiest way to do the striping would be to use "stripe/line" decals for the sides. The ends could be sculpted with the line decals, or cut from solid color decal sheets. While N-scale does make such freehand work a pain in the... caboose, its tiny size also means that you can easily conceal small goofs with a bit of weathering.