I oddly enough bought a t&d box the same as yours a couple years ago at a consignment shop that used to be a few towns over for around $10. It's pretty beat and the skinny part of the tray had a piece cut out of it. The box was also stenciled "pipe threader" so I figured they cut the tray so part of the threader would fit in the large portion. It's a good solid handbox and is currently full of used hydraulic fittings that often get me out of trouble.
I noticed it is very similar to a GMTK (general mechanics tool kit) box from WW2. In fact, it is identical, except deeper, or taller.
I wonder if T&D may have bought tooling to make these at some time, and tweaked the design a bit?