Migrated to:
https://www.printables.com/model/543301-beckman-circuitmate-dm-73-battery-cover-door
I've had this great little handheld meter since not long after high school (longer ago than I care to mention). You see them pop up on eBay from time to time, and I've purchased a backup, but the latches on the battery door are a weak point in the design. For 20+ years, I've had to put up with mine falling off, but I decided to make a faithful recreation today.