I recently ran into the best vintage automotive locksmith ever. He had all my 4 locks good as new in an hour. (They were BAD) He had boxes and boxes of old locks and all the blank keys you could ever need for any GM till the newest style began. (About 1400 different keys, all numbered) Best of all, he didn't charge for advice and info on anything.
To answer your question, I don't think locks changed much from year to year, series to series, just the housings.
