I just got my grubby paws on it a few hours ago. It is an older (by my youthful standards) strad, made in 1994 (serial number 424933). Have been playing and comparing to my 2000 strad for about an hour and a half (Arutunian's Concerto, Handel's Aria con Variazioni, Concone Studies).
Noticed the '94 is a BIT heavier than my '00, especially around the valves (The valve pops are noisier as well?). Both of these strads are model 37, with my '00 having the heavy caps option. Also noticed a lyre holder (?), and that the bell goes a bit higher up than my '00.
I was wondering if anyone here is an authority on the Bach Stradivarius, and can tell me what difference in the '94's build makes it so much heavier than my '00? Is it the valves (If I am guessing correctly, I am going to dance my happy dance

)?