Unusual chest of drawers

[Riverrat]

Hi folks, I just obtained a piece of furniture and am trying to figure out what it is.

The seller called it a silver chest as in for flatware but I don't think that was its original use, just what he remembers it being used as as a child.

It is a small chest of drawers. Total of 16 drawers. The top 4 drawers are the full width of the piece and the lower 12 are side by side.

The measurements are 39 inches tall, 29 inches wide and 13 inches deep.

It appears to be mahogany and of good craftsmanship. Drawers are dovetailed in front and rear

The strange clues that I'm trying to decipher are the following:

Brass handles on each side indicating portability

Each drawer individually keyed with a barrel key

No drawer pulls, the key is the pull for each drawer. Cabinet is flush with no key inserted. Perhaps to make it easier to load and unload. That would match with the portability.

Drawers are fractionally smaller with the bottom row being largest and slightly smaller as going up.

My hypothesis was military document chest but 13 inch depth and craftsmanship with reducing drawers doesn't match.

Medical or apothecary chest doesn't really fit because of the graduated drawer size and no dividers in the drawers.

I'm stumped. Any help would be appreciated.