I am a newcomer with the Flugel. ItÂ´s a Getzen from the 70Â´s that, after some work in it, is in very good shape. I play it two or three rounds a week and every time I take it out of the case I find it valve stucked like if I never had oiled it before. I tried different oils that last a lot in my trumpet. Is that normal with the Flugel or is there something I can do about it? Thanks.