I believe serial numbering with the R-9 started at 100 or 101?
Mine is an lower 900s number, so I'd guess there's probably at least some 800 Rohrbaugh guns around, probably more.
Eric, my Les Baer Stinger has a serial number in the 11,000 range. I know nothing of Baer's numbering system, but I'll bet there's a lot more Stingers than Rohrbaughs out there, judging from the commoness of posts about the Stinger on the 1911 forum! The Rohrbaugh is still really pretty rare, and most gun enthusiasts of my acquaintance have never seen one.