Raimey,
I suggest you read my remarks carefully, I did not say it is impossible to identify touchmark initials. I said it is difficult or impossible to do so. Also, I didn't say it is easy to identify trademarks, since there are directories of trademarks, I said they can be. If the B.M. (in script) is in a trademark directory, it is identified thereby. If it is not in a trademark directory and there is no touch mark directory, then it is difficult to identify. I would be astonished to learn there is only one possible identification for a B.M. (in script), considering all the German given names starting with B and family names starting with M. Also, I can believe some trademarks are not shown in some directories, so would not be easy to identify.
Mike