It took several years but I finally found a decent Security Six with the 2.75" barrel. For me that' s a bonus because I like short barreled revolvers. Won it at an auction in February 2020 . When it was all said and done with I paid $541.80. It was an internet auction, but the auction company is only a few miles from my house so I was able to give it a thorough exam before the bidding began in earnest. I got in a bit of a bidding war for it. It's a 151 prefix and a serial number search shows it being made approximately 1975. I am actually surprised that I won the bid. It was looking like I wasn't going to get it, but then with a few minutes left the competition just quit. The duty grips came with it. I bought the target grips from Ar-7. They first better. They are now on my 4" Security Six.