Dave, I salute your noble effort. I will be sending another care package, containing one Sterling 1/2A parts pack with motor mount, bellcrank, and horn, one loose Sterling motor mount, three bellcranks with horns, and I also have 4 of the Dubro #148 1/2A battery clips in package if you want them. Do you need any small line connectors? I probably have at least a dozen cluttering up my line clip box.
The motor mount in your photo looks like the Brodak one, or at least squirted from the same mold. Perhaps they will sell you some loose ones in bulk. Same goes for the bellcranks.
Bill Bischoff