

I'm not joking, but it seems to that we have a minor language problem here. Yes you have written that the assayer is Moor. OK, i buy it, but the important information is his (and Mitin's) working period in St. Petersburg. The YEARS!
Anyway, now you have the soot marks and I would appreciate you comments. I believe it is a Moor but not Mitin (according to you).