Your post has intrigued me since I had a Star in 9mm about 35 yrs ago. It was good gun. Fun to shoot and fairly reliable. So I did some research and found the following information:
They were made from 1970 to 1987, with only a total of 7,657 made. The majority (4,525) were made in 1973. The company went bankrupt in 1997. On a couple of auction sites the guns are selling anywhere between $500-$600, depending on condition.
I am sorry, I have checked every possible source for magazines I could think of and there is not a one available. Having so few of the pistols made does not make it any easier. You have a fine piece of history and a shooter, but in a way it would have been better if it had been a different model. Good luck in your search.