Mark I or .22 Standard

[Ak_Red]

I have a ruger .22 pistol I am trying to ID. I was told when I bought it ($50.00) it was a Ruger Mark I. But, nothing other than print on the inside of the pearlite grips saying it is a Mark I ID's it.

It has the "bump" for the follower button on the left side like the A-100 frames, but does not have A-100 stamped on it as I am told it should.

It has the 4.75" barrel, which indicates it is a Standard .22 and there are no markings on the pistol that say Mark I. It does not have the warning label.

I called Ruger (got voicemail, of course) and left a message, but have received no answer. I am assuming I have a Standard model made sometime between 1971 and 1984 with a set of Mark I grips. Anyone have any info that will help me nail it down? Thanks!