I have two The Martin altos, one is a '49, one is a '54. To my surprise, when I got the '54, I noticed it had a slightly more narrow bore, and is a little heavier. The bell is also slightly more narrow. The tech set up the key heights slightly lower on the later model too. I prefer the '54 so far, but last night while playing I noticed that I kept playing middle Bb bis slightly flat, and I got the impression that this note on the the '54 plays a little more flat.
Is this kind of variability normal between saxes? Is it just something I will adjust to and shouldn't worry about?