Security Six-15-20 $ tops.
Ruger Security Six or Police Service Six, but I'm not sure which series they are for.
There was an early version for 150 Series guns and a later version for 151 series guns and later.
The 150 series is scarcer, and usually a bit pricier.
WAG pricewise is $25.00 <>
Myron
JimH,
You posted while I was still typing,
Judging from condition, you are probably closer on price, but again may vary for a 150 series.
Myron
Thanks guys, this makes sense now. I remember my late dad owning a security six...I remember it having black rubber grips on it. I bet this is the original set. Again thanks so much