So I just got this alto from eBay. I was a little bit nervous about it but I think it is legit. From my little bit of research I’m thinking it’s an A-4 built in1977? Wondering if maybe it’s a 500 series? I got it to replace my YAS-23 that I stupidly sold last summer. It seems picky about mouthpieces and so far only likes my Selmer S-80 C* mouthpiece. Any recommendation for a jazz mpc? Any other thoughts on this horn?