SPT: Stackable Part Trays

Simple stackable trays, roughly 3"x5"x1 (76x127*25mm). Internal fillets to make getting small round objects like drills and end mills out easily. Split variants will fit two wide on top of a full sized. Two types with internal partitions, a full height and a half height.

I've included step files for all variants; should make it easier for people to modify to suit.