A fellow had a Canadian Tire brand Mastercraft 12V electric drill (54-295-8) with charger and case he was going to throw away because a replacement battery was not available. I nabbed it. Unfortunately, he had previously discarded the dead battery so I couldn't just rebuild it.
Instead, I had to design the battery case from scratch to fit the drill and a fistful of sub-c NiCd cells that I had from previous projects. Took the better part of a week to measure up and design (but I'm retired and in covid lockdown, so a fun thing to do). Printing took about 7 hours overall.
This is only the case build; photos of the battery rebuild (and probably some updates to the 3d print) to follow.