As I recall the A9 would be the serial number of that mouthpiece with "A" being the first run from around 1994-1995. I believe only the models sold by Orfeo had the serial numbers.
I understand that Deck Mouthpieces made after about 1997 and those sold by Brasswind (I believe only sold by them after 1996) do not have the serial numbers.
FWIW, I have the actual master of the Warren Deck 2 and find it to be an extremely close match to the feel of the PT-50+ in sound colour, throat, rim shape and size.
Dave Houser Mouthpieces Works manufactured the Warren Deck series.
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