@Mattax
Curious...how did you decide to measure that stamp as you did for the pic? You put scale in perfect location.. I see pics frequently by people who collect, that can't seem to get it right or don't even know 'size matters' (lol)
I had found a reference on-line where it gave dimensions and it was in mm. I wasn't sure where to line them up but figured it was probably the outer lines of the printing.