Quoted from dsuperbee:
As a follow up, the motor arrived and until I can find a place (or figure out) to raise the gear up on the shaft, it won't work. The gear is pressed on the shaft almost all the way down, instead of at the very end. So even though it is listed as being able to work with DW, it won't without some finagling of the gear.
So, the gear is on there, just in the wrong position along the shaft? That stinks! Feels like you would need the equivalent of a brake hub puller to press grab the edge of the gear and apply pressure to the shaft.