So I found myself typing to this to a chap over in airpistols trying to date his Benjamin-Sheridan CO2 pistol:

"I do not know if the Benjamin/Sheridans adopted Crosman's post-1975 serial number formula, in which the first three or four numbers are the month and year of manufacture. If they did, then mine is from November (9) 2008 (08), and yours from July (7) 1998 (98). Which is about right for mine, and would make yours a late Benjamin Sheridan E. (Incidentally the first three digits of my very late Blue Streak are 490, which would be April 1990, and also makes sense.)"

So does anyone know for sure if Benjamins and Sheridans made under Crosman ownership use the Crosman serial number convention?

Strong circumstantial evidence above. Guy thinks his gun is a 1992-98 Benjamin-Sheridan. Serial number is consistent with that. I know my pistol is post-98. Serial number is consistent with that. I know my Blue Streak is post-85 (factory drilled and tapped receiver) but pre CB9 (1991-2?). Again, serial number is consistent with that.

Anyone? D T Fletcher?