The original P&A's had what was called the "Hands On" stamp, which transitioned to the chains stamp. The chains stamp ran pretty much through the 90's, the barstamp was '00-'02 or '03 and sometime in '03 the swoosh stamp came out. I forget when the switch back to beadless was, it was sometime in the '00's.
I was waiting for you to chime in! So it's four stamps since the "Hands On" and "Chains" are different.
Takeaway is yes, both beadless and small bead existed for DX San Marino P&A's. Cool.