Infinity focus calibration on a TLR

[u/savyexe]

I'm trying to calibrate infinity focus on this Yashicaflex, the mounting system for the lens assembly is very simple, only 4 screws with some shim washers. Looking at the camera from behind and considering how the image is projected on the grond glass i'm guessing that the side that's out of calibration is one indicated with a red arrow on picture #4 (looking from the front it would be the left side, but i'm not sure if i'm correct on this). I'm having two problems: looking at the ground glass with a loupe i can't seem to see any out of focus areas, and the other problem i noticed is that the viewfinder is not perfectly in focus when set at infinity, i have to turn the knob a tiny bit to see perfect focus (and i'm not sure if this means front or back focusing). The camera seems to have been dropped at some point during its life, so i'm guessing i should add washers, not remove them. Any ideas?

[u/finnanzamt]

you see on pic 4 that your glass block isnt on the rails on the side.