I've been looking at the aLOKSAK bag sizes and reviews, and they make a 12" X 12" that might be an excellent fit for an 8" X 8" X 2" solid plastic container --- or might even fit the larger of the two Trangia aluminum (mess) boxes (which are not waterproof, but otherwise make great medium sized survival kit containers).

In other words, you could add water-proofing or an additional level of water-proofing with an inconsequential gain in weight and bulk. + the bag itself has other uses.

LesSnyder - your suggestion definitely warrants a test. Thanks.

Grady