Ah. Pretty sure that they're going to be needed permanently. An Audi 5000 motor is being dropped into another car, and in order to drive the fuel pump, we need that gear and sprocket. Since they have to be matched, we've got to have both, and since the drive gear has to fit the smaller, older-style pump shaft, we're limited to using these ones.
So the loan offer is much appreciated, but I think we need to actually buy / trade / otherwise acquire them permanently.