I have a 1987 GP-9 #8800 from 1987, which is from the “Black Diamond” set. I seem to have sheared off the center idler gear from the horizontal motor truck. I’m having difficulty finding a P/N or identification of any kind online to begin my search for the correct replacement part. I assume I need the truck frame at very least, as the shaft the gear would ride on is gone.
I’ve read that other engines (GP-7, GP-38, GP-20, U38B) from the same era shared many components like the frame among other things. If I cannot find the identical part, would any of these suffice?
Thanks in advance.