Size 1 - measures up as 23" P2P, but due to the fit across shoulders (18"), I would say it would suit anyone who normal wears 21.5 - 22" jackets. No bigger.
In excellent condition, wax looks new. Drawstring at hem has been removed. I have the drawstring and toggles which I'll put in the pocket.
Apologies for the quality of the pic (taken with a phone)