Buffet clarinet model help

What is it? It's OLD. Sorry, couldn't resist!

Have you checked out clarinetperfection yet? Steve might have something on there that could help.
He has a pretty good list of serial numbers and model information.

The wrap around register key is pretty cool. It's not 'unique' to Buffet clarinets though.
I have a Buffet, Farney, and J.W. Pepper Albert systems with one. It might be safe to say that it was pretty much 'standard equipment' on clarinets manufactured before 19XX.
I'm not sure when everyone went to the register vent above the F thumb hole.

No need to get pissy. I only wanted to clarify that the wrap around register key was not unique to Buffet clarinets.
The examples I used were just that. Examples of different brands that just happened to be Albert system horns.
They did carry this feature over when they started producing Boehm system instruments. That's why I use the date 19XX as there was an overlap while they made the transition between systems.