Raimey,
Thank you for your response. It looks to me that the right barrel is stamped 10.45mm Above this there are three stamps (crown over S,B,U). the circle looks like it contains the number 44.
On the left barrel above the 5.3mm stamp are the crown over G,B,U.
What tells you that the proof was done in Zella-Mehlis and in the final state ?
Otto