I wonder if it says MDY, which would make the float bowl from a 1928 bottom feed touring carby. I think that the pinch bolt clamp in the bowl lid is also a 1928 thing, and by 1929 AMAC had joined with B&B and Binks to form AMAL.
[edit: It seems the pinch bolt on the lid was used on AMAC TT carbs from 1925-on, but only in 1928 for the touring carbs. However the TT carbs had joggle in the arm to the mixing chamber to set the fuel bowl lower, so yours is the touring model.]
Cheers
Leon