Yesterday I filled a hole in my Six series collection. Got a low back (150- s/n) Security Six, .357 Mag,
2 3/4" barrel
Stainless Steel. I have a 4", now need a 6". Now on to see if they made any stainless fixed sight (now called the Police Service Six or Service Six) in 2 3/4" and 4"
Reading the RENE Reference of Ruger Firearms, Ruger probably did not make any Stainless low back fixed sight models (either marked Security Six or Police Service Six) BUT, with Rugers you "Never say Never". Same with the stainless 6" (only one of which is known - but you never can tell

) The hunt is on.