God I used to hate those snaps...such a pain in the arse, especially once you see how simple the TJ tops are.
Back on topic though: My old YJ only had about 6 snaps total. I just kind of rationed them between the drivers and passengers side and spread them out as evenly as I could. I looked and never did find any. The dealer told me I had to order a whole top so I just decided it was fine how it was.
Sorry I'm not able to help solve your problem.