I have an older Ruger 22LR automatic that was given to me many years ago. I have lost the magazine to it through multiple moves over the years. I assume it was manufactured in Southport, Connecticut as it has it on the side of the barrel. The serial number is 286380. I have been unsuccessful at finding out information. I wanted to know the model, when it was manufactured and where I might be able to buy replacemnt magazine(s). Any assitance would be greatly appreciated.