According to Flaydermans, that serial number (range from 14400 - 187000) should have a barrel address of:
ADDRESS SAM COLT/NEW-YORK CITY
But he notes: "two variations in markings known." Though the variations are not listed.
Flaydermans suggests further readings: Shumaker's
Colt's Variations of the Old Model Pocket Pistol and the "highly detailed" Jordan & Watts
Colt's Pocket '49. In those books, "among details considered are markings, types of trigger guards, loading cutouts, loading lever latches, sights, hammers, finishes,
engraving, etc."
If the original "Colts Patent" had been filed off, would there have been enough metal to engrave the current letters?
Check this out:
http://www.rockislandauction.com/vie...id/52/lid/1275
I would definitely have it appraised.