I have an old (late 1940s) Mark II that is still competition quality accurate. Gas ramp keeps it dead on between shots.
Kind of hard to have a MK II from the late 40’s when they were not made until 1982
The Ruger Standard model is a firearm introduced in 1949 as the first product manufactured by Sturm, Ruger & Co., and was the founding member of a product line of .22 Long Rifle rimfire cartridge pistols.
The MK II (”Mark Two”) was made from 1982 to 2005. Previous models include the Standard, Ruger’s first model, made from 1949 to 1982