Was given an original red-eagled Ruger .22 std auto pistol. Bought a magazine for a Ruger Mk 1 that the store owner said would be the right one. It isn't. Loading button on wrong side. Which magazine do I need? Help me please.

Take it apart and put the button in from the other side.

First make sure it is an original. If it is, the Mark I should fit. They made some anniversary additions in Mark II that also had the red eagle on them.

all mark I are the same. swap the button over

Thanks, Guys, I knew this was an original because my step-father had it when he married my mother in 1954. he gave it to my half-brother, who just died, and I was given it by his wife.
Max