Whoops. Sorry about that 
Where is the Bass Artist that you mentioned?
No apology necessary. When I checked my files, I only have this serial. Apparently the previous photos were only good enough to confirm the serial and I didn't save any of those. This newer listing on Reverb has superb photos despite the error on the serial and it gives me several good views of a 7-ring articulated from this period, and eventually the changes in those kind of features will allow us to "spot" date examples even if the serials have been erased or worn away. This in NOT the same 7-ring mechanism that was used by PM during or just after the partnership with Pruefer.
We can separate the wheat from the chaff here. Don't stop harvesting.

Do enough research and you can take this project over and I'll get on with figuring out the Bettoney serials. I went for PM first because not only was my best player at the time an Empire of undetermined date, but this was a company with relatively low production numbers and probably they made no stenciled instruments at all. These will always be relatively more rare than other USA makers that engaged in almost mass production. And then there is also Pruefer to decipher, which looks far more straight forward. We need all the good intelligence agents we can get here.

H. Bettoney might have made more woodwinds than Selmer USA up to the time they disappeared and the stencils are numerous and serialized like the ones carrying the Bettoney name. That said, the system for serialization at Bettoney is daunting.
Harry Pedlers are more rare than Penzel Mueller clarinets but most have NO serials. Thanks, Harry! Pedler Woodwind serials is another puzzle. And then there are the Bertelings;- I might have seen about 5 of these that weren't already in collections.
The Penzel Mueller bass? No reason not to disclose where it is, it's been "discovered" and ends on a Sunday.

While the reported serial is quite plausible, I am trying to be very careful. You might note that I did include a few serials with some blanks in them, but these were only very rare model types and far less likely to introduce confusion than a mistake on a more common 17/6 Boehm Bb. I thought it better to record the rare model partial serial than leave it out, so I have made some rare exceptions to the rule, but only concerning a rare model.
I'm saving some of the photos of the bass, and if we find another bass with a similar serial reported that looks like this one, I might decide to insert it with the reported serial at that time.
Concerning the chances on that currently listed bass, don't bring a knife to a gun fight as they say...
http://www.ebay.com/itm/Vintage-Penzel-Mueller-Wood-Bass-Clarinet-Serial-L10043-W-Mouthpiece-Case-/162617628350?hash=item25dcc416be:g:XhwAAOSwQQdZhOHlI'm not in that auction. The winner will probably be a sniper using a bazooka.
