Re: Vintage Conn Saxophone
By serial number it looks like 1926, but the Mseries is listed as 1934. Perhaps someone else can shed more light on that for you.
The saxophone is an alto (Eb) but it is constructed to play tuned to High pitch (that's what the A and the H before and after the serial number mean). Low pitch is the standard today, so this instrument will not play well with modern instruments, though it might do fine with other high pitch instruments!
The other engravings are most likely:
PA APLD For DEC 3, 1914 along with the Patent number. The same number and date is on most (if not all) Conn saxophones of the period.