The Model 60 was made from 1960-present, while the Model 99 and 99C were made from 1959-1978. Both are the same internals, with just cosmetic changes. Cheap, entry level semiautos, that can have problems, but then again some never have problems.
I've got a Model 60 I bought new when I was 18 and after over 40 years, it still functions perfectly, and it's never been worked on.
You might get the stock to look better, but it's most likely even if you did, it's not a very expensive gun, and begs the quuestion, "Is it worth the effort?"
