My first handgun was a Ruger RST-6, pictured first below. It is generically called a Mark I, but Mark Is were the adjustable sight models. I liked it so much that about 10 years later I bought the KMK-512 version of the Mark II. Difference in price was astounding, $92 for the RST in 1979, $259 for the Mark II in 1989. But I wouldn't give up either.
