Old-Win.
I don't know if anyone wrote a book with photos of inspectors cartouches.
I was able to find photos of Orville W. Ainsworth's cartouche on other guns as he was a well known and active inspector during that period.
Inspector’s marking “O.W.A.” (Orville W. Ainsworth) 1831-1870.
Smith & Wesson American 1869, Remington’s, Colt Percussion and conversion revolvers 1831-70.
It was Ainsworth that inspected the Colts used by Col. G.A. Custer's 7th Cavalry at the Little Bighorn.
Orville W. Ainsworth served as an Ordnance Sub-inspector at the Colt plant from mid October, 1873 through November 7, 1874.
It was Ainsworth who actually inspected the guns in the serial range of 200-14,343. This was the block of guns which were used during the height of the Indian wars, including Custer’s famous Last Stand. (June 25 and June 26, 1876)
The cartouche used by Erskine S.Allin.
(You need to Login or Register to view media files and links) His cartouche is shown on the stock of this Model 1860 Spencer carbine together with two other CW inspectors stamps.
(You need to Login or Register to view media files and links) (You need to Login or Register to view media files and links) (You need to Login or Register to view media files and links) My understanding is post CW conversion Sharps carbines had a DFC-David F. Clark cartouche on the stock.
Post CW Spencer conversions had an E.S.A -Erskine S. Allin cartouche on the stock.
David