Here is a picture of a Mod 36-1 Target. It dates to Oct 71. I was always told it can't be. None were made that late. It letters as a 36-1 fixed sight, but the work in factory quality. Unfortunately I can't get any other search's as records have not been digitized up th that date yet. My opinion is that it was in inventory as a regular 36-1 and they received a request for a 3" Target so it was pulled from stock and converted. It just can't be verified.
I gave up trying to document and gave it to David Carroll for some future auction.