There's an aftermarket latch you can use that slides on the edge of the glass so no drilling is required. I got a couple of them years ago at Voluparts in Atlanta, but I think I recently saw them in IPD's mailer. They work pretty good.

Are the pivot fittings at the top still attached good? If not, you should be able to reattach them with that rear view mirror glue. That glue never seems to work very long when used to attach to latches however.