Hmm..I have logged my Taxi on ipsnd.net also. It suggests ~7,300 games produced based on the serial # ranges logged.
166113 Mine is an original Marilyn - it is a German reimport - with German instructions cards and coin mechs
There was a good number of Marilyns made (both domestic and International) - I think 2,000-3,000 if you extrapolate the data.