Desktop organizer - Modular Storage System

This could be a remix but I can't point to multiple origins and I designed all from scratch. However I tried several designs which just were not THE thing for me ;) Especially connections were not the dovetail which I happen to like.

Inspirational thanks and credits for seeding my thoughts will go to
- O3D https://www.thingiverse.com/thing:2539830
- O3D https://www.thingiverse.com/thing:1743145
- gpvillamil https://www.thingiverse.com/thing:421886
- AndrewBougie https://www.thingiverse.com/thing:1489606

I wanted to make modular, stackable interlocking system with some extras. Also wanted to make it relatively easy to print.
Module size is 40x40x80mm. (M in STL-names, so 2M is 40mm high-80mm wide-80mm deep)

You have different drawers for every module size (1M, 2M, 3M)
Single drawers, divided 50-50 or even 4x25.
One 1M drawer is for SD cards.
(I printed and colored SD card from Ubergeekking https://www.thingiverse.com/thing:710938 and glued that to SD drawer)
On top yo