I have a speedmaster professional, serial 77048xxx, the back of the case is the steel one with the seahorse/first watch on the moon. Manufactured in 2000 I believe.
I'm trying to find the model number, not the serial.
It will just say 145.0022 inside the Caseback. Like every Moonwatch from around 1990 onwards. I think he wants the PIC. For that model, it will be 3570.50.00