hittman said:
This is why the low back stainless guns are so dang hard to find!
Yes, and fixed sight stainless low back guns may not exist. I have low back stainless adjustable sight Security Sixes in all 3 barrel lengths (the 6" is very rare and mine is a 151 prefix, I believe there is only one other known). Although the GF fixed sight guns (square butt, later called Police Service Sixes) are listed on that price sheet, I have never seen one. And I firmly believe there were no low back stainless Speed Sixes.
My lowest number stainless gun is 150-55xxx and it was shipped twice, once in 1975 and again in 2009. Somewhere in there, it got a high polish finish done to it and when shipped out in the warehouse cleanout of 2009, it had a barcode label partially obscuring a hand-written "High Polish" on the end of a 1990's style yellow box. I suspect it was returned for some reason (possibly a gunwriter's demo or salesman sample) sat around possibly for years and was then used as a test subject for the high gloss stainless finish first introduced on the Vaqueros and later on other models. Although shipped twice, it does not have a "S" (Second) serial number. It is a GA-32 Security Six with 2.75" barrel.
In general, the high back blue guns started to appear in the upper end of the 150 prefix and the low back stainless guns continued a ways into the 151 prefix. I don't believe I have seen a low back blue gun with a 151 prefix. In general, the low back stainless guns petered out in the 151-0xxxx range, my lowest high back stainless is 151-12xxx, but the 6" low back is a very odd duck at 151-26xxx, so I suspect Ruger turned up a few unused stainless low back frames at that time and happened to put 6" tubes on them.