Here's my finished print of the 1:100 (15mm) Grosstraktor, and it's pretty ropey.
I could find no information on interwar German tactical markings at all, so I made them up based on the sorts of crosses that appeared on German tanks in the last days of WW1.
It was printed on my Ender 3 at 0.1mm. I don't recall where I got the model from; it was quite some time ago. I assume it was probably Thingiverse.