the later ones usually had the numbers electric penciled on them, but they may also be located on the rear ,not the face of the cylinder, seen them BOTH ways, as well as the "spare" (ACP) cylinder being marked and NOT the 'main/primary ' (LC) cylinder in the gun....but again, MOST of the time they were both marked on them 'later guns',,,,,,,,,,,,,,,,,,,,
never say never, and never say always 8)
Aside from the 'fact' one really NEEDS either the original 'marked' (X) shipper, with the "package" and /or a letter from the records department would help......... :wink:
LOTS of "put together" ones are now out there over all these years. :roll: