Removing mini wideset handles without set screws or mounting nuts
The faucet is a Moen, model 4560.  It was imprinted (but mostly worn away) on the back of the faucet spout.

All guides and videos say that the bulbs on the handles just screw off easily.  That wasn't so here.  In the end, after numerous attempts, I hack sawed off the handles.  Not elegant but in this situation it was what was required.