...old lady forbids me from spending 800 to 1000 for a single tiny brass train as she says it and I don't want to sleep in garage the roof still leaks I'll fix it eventually lol
Lessons I learned the hard way:
1. If you stop using the term "old lady" and substitute "my lovely wife", your model railroading budget will increase. Just sayin'.
2. If you are going to collect brass, you should spend an equal amount on jewelry and fancy restaurant dinners.
3. A good air mattress, sleeping bag, and tent are more comfortable than the garage, at least, more comfortable than my garage.
Kidding aside, I have a similar project requiring a Con-Cor Hudson shell swap onto a Bachmann 4-8-2 chassis. I don't really know where to start. So I hope you get some responses, and I learn something.
I can't speak to your particular project, but I have noted that, while there are precious few locomotive prototypes produced, there are several resin casters and 3D designers out there offering cabs and various domes and such via shapeways or other outlets. The correct cab goes a long way toward giving the right "look" to the otherwise generic USRA loco shells.
So best of luck. If I stumble across any SP resources while I am working on my (hopefully soon to be GTW) loco, I will pass them along.