Drum roll please....Dave is correct, drive-side main bearing puller. However, I will now, also, be using it as a dinosaur egg cup. Groily, thanks for the idea.
It's made from a door hinge, two bits of aluminum, a thick scrap of lexan, some all-thread, and miscellaneous screws and nuts. (No comments about which nut has the screw loose, please!)
Richard
P.S. Apologies if this is more photos than it's worth.