Cutting large O scale diesel shells for kitbashing

Tools, Techniques, and Reference Materials Techniques
1

I’m working on two kitbashing projects in O scale: Kitbashing Atlas F9 shells to make a GMD FP9, and ALCO shells to make a MLW RSC24. Anyone have recommendations for get clean even cuts?

I’ve tried a razor saw and rotary cutter with mixed results. I’ve clamped thick plastic strip to the bodies as a guide. I have a couple of bodies to practice on. The first few attempts, I cut the sides first, but I’m thinking I should work on the roof first, then match the sides to the roof cuts.

2

I’d scribe it first, get it right, then use the razor saw in the scribe line carefully. At that, plan on some sanding using a sanding block. Just the same as following scribe lines to open up doors or trunks on model cars. At least that’s how I’ve done it.