Frame manufactured in 1862. Mixed numbers including serial number "118000" marked on the frame, "142970" marked on the barrel and triggerguard, and "48757" on the backstrap. Boxed script inspection cartouches stamped on both sides of the grip. Two other examples with this same type of unknown experimental rimfire conversion cylinder are photographed and described on pages 210 and 212 of "The Book of Colt Firearms" by Sutherland and Wilson. The gun photographed on page 212 has backstrap numbered "142970" and "48757" on the barrel and triggerguard, which matches some of the numbers on different components of this example as well as the gun photographed on page 210, indicating these three guns were all converted and assembled using each others parts. The book indicates these rare unknown factory experimental conversions were done c. 1868-1869. This revolver is photographed and described on pages 409 and 410 of "A Study of Colt Conversions and Other Percussion Revolvers" by R. Bruce McDowell. Provenance: The Phillip Otto Clark Collection