Ok I see it's a cap, orange white yellow = 394= 0.39 uf
Pick out any Fincor units you have that you think might still be good, check that the SCRs are all "IS68" and if they have insulating mica washers. If they do, you could try hooking one up.
Terminal 2 and 3 are definitely motor wires, Terminal 1 is neutral and 4 is 115v hot I'm certain now.
I see where the field would connect but it's a factory option, not connected on yours.
Mark