Originally Posted by
cudak888
Mistake by the BB manufacturer? The stamping blank would have been in the correct orientation; could be someone screwed up and forgot that it would wind up reversed when transferred to the shell.
-Kurt
Yes, that's a possibility. If so, the stamping die must have broken sometime between 1980 and 1981, as the I've seem frames with 1980 S/N having the correct orientation. You can't reverse the orientation on a stamping die or mould insert. They would have to have been manufactured incorrectly.
The only situation where it could be reversed would be if it was milled using a through-hole template. I know that Marinoni had a pantograph milling machine but typically templates are blind hole, which would make reversal impossible, unless the template was in error.