The model number on Aulos altos is printed on the recorder itself, at the narrow end of the main barrel (near the foot joint), on the bottom. There are two 509 models – the 509 (an earlier version from about 20 years ago) and the 509B (current version). So if you mention the model, be sure to designate the full number. Just FYI, the “B” does NOT stand for “baroque fingering” as it does on some other manufacturers’ model number; on Aulos, it just stands for the version number.
Indeed. My first recorder, bought new in 2016, is an Aulos soprano 303E, or A. It doesn’t rate well on Saunders Recorders (tho it sounds fine to me) But there is a much earlier soprano with the number 303, which does get rated well.
You don't stop playing when you get old. You get old when you stop playing.