Thanks to Dwight Ridenour for giving me the opportunity to review this neat High Pitch Albert System Couesnon.
This has the nice improved action where low F# can be fingered using just the low E key and not using a right pinkie, and similarly of course for middle C# and B. This has excellent forked tone for Bb/F.
The bell is lavishly marked, starting with Bb HP, then 1900 Exposition mark, then the regular Couesnon oval logo. Then beneath that is:
This clarinet is quite well in tune. It is sharp as is typical around low D. When testing with my tuner, each pitch hovers right in the crack for modern tuning. So, yes, it is a High Pitch instrument. And quite fun to play.
I did not find a serial number or a batch mark under the keys.