The BEJ serial number prefix was being used by the factory in.....
January of 1990.
Give or take a month either way. Which is normal.
The problem is with the Standard Catalog is not the triple alpha s/n. It's the way the catalog is written. I have my own data base independent of the Standard Catalog. In the real world the prefixes were issued by date in a near perfect alphabetical sequence.
S&W did throw a few curve balls with the serial numbers. Probably to confuse their competition from extrapolating Smith's production numbers and manufacturing capabilities.