Here is a Table of BB numbers one of our esteemed members assembled.
PAM_table_v5.0.xls
The BB number is comprised of the Year manufactured, lot size and serial number
Definately a Sandwich crystal so aftermarket cyclops is nearly impossible...
Also not that you have a Hashmarked bezel which came out on the "D" series and above 024 Submersibles....
The "A" series has a non-hashed polished Bezel....