There has been a number of these gunsights listed in the various auction houses, interestingly PATT.G328Y is nothing to do with a patent number as David and myself mentioned it’s too short, also the abbreviation for a patent only has 1 T.
Patt.G328Y refers to a pattern number, the picture which I have hopefully uploaded shows a case in which the instrument was kept, stenciled on the inside of the lid is the pattern number.
Daryl
