Having repaired woodwinds for a while in the 70s, the rubber band trick to seat the pads is pretty standard solution although there are little jobbies to do just this. Thread around the tenon joint will keep the joints fitting tightly. If you have a little leak it can be found by corking the end of the instrument, closing all pads and blowing smoke with moderate pressure through the mouthpiece. (in the case of a recorder you need to stip the fipple also) It will readily show you where the small leak is so you can attend it. Haven't thought of these things in 30 years! jimmyt