Really nice work! It's when I see models in small scales like these that make me wish I had 3D printer...
scaling down is still fraught with many problems
The main one is the fragility of some parts (first of all, these are gun barrels)
When a friend asked me to make miniatures of the BMD 2 on a scale of 1:200 for him, I had to redo the 3d model - to thicken the gun barrel and the thickness of the tracks