Rare Charles Bay Clarinet

Purchased a long time ago. It does produce sound, but it would be best to have it overhauled. It can still be used if the tampon is replaced. One key has been modified, which looks cool. It came with a tag indicating it was customized by Charles Bay.
This is a rare item that will likely never appear again. I have never seen it on Yahoo Auctions, Mercari, or in music stores.
Details are unknown, but it is believed to be a very valuable item. I am open to price negotiation.