Hi, I restarted playing at the beginning of the year after a 20 year break, have bought a new (to me) sovereign 928 cornet, and initially was using a new Denis Wick mouthpiece, but found and am presently using my old mouthpiece, a KosiKup which I have had since I was about 12 (i'm now 60). My question is is there any reason I shouldn't use this mouthpiece,? it's comfortable, I'm having trouble in the upper register, but think that may just be the length of time I stopped playing for. My only concern is that obviously there has been changes in instruments over the years, but has mouthpiece technology changed, and would I be better trying some more modern mouthpieces. What are everybody's thoughts?