Hi, any Berg experts out there? I have a nice playing steel one, and am curious about approximately when it was made. It's a wide body, duckbill, 110 2 M. The M is directly under the 2. Both the ligature and the piece say "Reg. Design 851427/8". The ligature has the screws with round knobs (not paddles) that're kind of rough like a finger-nail file. Any idea? Thanks.