You should try Smokey Valley Railroad and Machine. Will have to do a search, I can’t find my info and phone number for them. They are a small outfit and a pleasure to talk to. You may only want to buy the stanchions only instead of the rail kits. The long hood railings are 2-3 piece. I bend brass wire to fit and solder to the shanchion. If you are painting your shell, you might want to hold off until you have the stanchions for actual fit. Front/ rear stanchions will mount differently pending what loco you’r working with. These parts are superb quality and match prototype. Good luck in your search.
Bob K.
Precision scale also makes nice stanchions. I use the brass ones and bend my own handrails from brass wire, then solder everything together. It’s a lot more durable than glue, and the handrail assemblies can be removed easily if needed (provided you don’t glue them to the locomotive). The Smokey Valley kits are nice, too, if you want the handrails pre-bent.