Based on the many useful comments and suggestions here, I found
Delrin® Ultimate EDC Capsule (Waterproof) I checked with CountyComm and quickly got a reply they haven't depth tested it. I'm going on river rafting down the Grand Canyon, so figure I can use it anyway. In the meantime, a buddy who services lots of dive gear and is a Suunto authorized repair center has a pressure tester for battery replacement. I figure I can pop this in his tester, send it down to 6 ATM for a few hours and see how it holds up as far as being water tight. I'll also test an old GoPro case and dive light to see if they hold up or collapse with no contents inside in his tester
I've never bought anything from CountyComm before, so this should be interesting.