Thanks for the advice, Henry D. That silicone sounds like a good solution, an I will try it and let you know how it goes. I am not likely to damage the horn with silicone anyway.
Just to clarify, the slot has been extended deliberately, and quite neatly. I also suspect that it was done in order to squeeze the neck around an undersized tenon. Whoever did it cut way to far down though. I am surprised that this wasn't fixed, because I ordered the horn from Saxquest, and I figured they would notice that the horn wasn't playing right. Other than the neck problem it has a really well done fresh re-pad, and was sold for a great price.
Just to clarify, the slot has been extended deliberately, and quite neatly. I also suspect that it was done in order to squeeze the neck around an undersized tenon. Whoever did it cut way to far down though. I am surprised that this wasn't fixed, because I ordered the horn from Saxquest, and I figured they would notice that the horn wasn't playing right. Other than the neck problem it has a really well done fresh re-pad, and was sold for a great price.