I just replaced the broken slider-latch on the rear window of my 1987 J-20 with a C.R. Laurence DVL2 metal latch;
https://smile.amazon.com/gp/product/B002CXH0YM/
it fit great, and was easy to install.
I added a short video to my channel documenting the replacement (I also speeded up the drilling, as that's a tedious thing in person, never mind on the screen...):
https://www.youtube.com/watch?v=df1hY6DHWLo
I hope someone will find it useful.