Can you carefully remove the stem and see if there is a crack/damage in the face of the mortise/ shank ?
Always turn it one direction only ! Never wriggle it out !
As you have heard Les is pretty much retired from carving. I believe he does the silverwork for a few carvers. His pipes are well thought of. I don't think he commands any kind of premium because he has a rather low profile. I don't think it would would bring much more then a $100 on the market.