Thanks Sorta-
...and to add a bit of clarity, it's a 9mm Interarms Firestar inherited from my father. I understand Interarms is no longer in business. Looking at the Surefire site it's difficult to determine which, if any of the adaptors might work.
It's not a big deal, just thought if there was a 'generic' mount out there, I'd add some light to the fire (so to speak).