Welcome, and thank you for sharing your clarinet.
What you have is a 17/6 Boehm Couesnon, with a nice (incorrect, yet still valuable) Penzel Mueller barrel and likely a "throw-away" mouthpiece.
If it were me, I would list it as a Couesnon (said, "Kwee-noh") with a PM barrel, and not include, or at least not spend much time mentioning the mouthpiece. Just because it's not stamped does not mean it's not valuable, but it probably is not, (if it is indeed plastic-- or "resonite") and a good many clarinets are sold without them, anyway. Should you determine the mouthpiece to be hard rubber, and of similar vint to the clarinet, then you may have a valuable, unstamped piece that deserves further consideration.
The bell does not match the rest of the clarinet, IMO, despite the fact that they are all Couesnon. While it was not uncommon to mix Grenadilla with ebonite or bakelite, and many manufacturers did it, there are tell-tale key work signs that depict the clarinet being made after the bell was made (circa 1901-1907), though since I cannot see the bridge key mechanism or count the posts for the lower and upper joint trill keys, I cannot tell if it were made after 1940. The fact that your upper joint has an adjustment screw for G#/A leads me to safely conclude that it was manufactured at least after WWI, as there were very few manufacturers making use of that feature prior to 1920.
Grenadilla is a type of ebony wood; when you see ebony wood listed in an auction, it is either because it is of unknown construction, or almost black in color--or both. It's a loose term, and not terribly definitive. Some Grenadilla is medium brown, but some is almost black.
If you can tell us (or post photos) if the lower joint's LH pinky keys are mounted to a single post or have their own individual (2) posts, and whether the RH index trill keys are mounted on 3 or 4 posts, as well as a photo of the bridge key, we can help you better determine whether the upper and lower joints are pre-or-post WWII. Also, not that we need it, but the presence or absence of a serial number on the upper/lower joints assists in the evaluation process, as well.
Certainly, this is not a worthless clarinet by a long shot, and while you "could" donate it to a local school, it would be undervalued and underappreciated in the hands of a child for a multitude of reasons, not the least of which would be that the band teacher's appreciation of it would not likely be that of the next "rightful heir". It would not likely be set up correctly, and suffer from poor playing as a result, and ultimately be relegated to white elephant status. Some of the best instruments are "Frankensteins", but most people judge books by covers and a lot of good things get overlooked as a result.
If you are intent on getting rid of it, I would suggest that you attempt to sell it on-line, and start the auction low. Provided you display hi-res photos from multiple angles, those who bid will know what it is, and will ensure a good new home for it, whether you make a fortune on it or not.
I hope that helps, and post more photos/information as you are able.
