I have single panes in my 72. After much online searching for the proper gaskets, I purchased gaskets from CR Laurence (same as VTS) The gaskets have "ribs" that make it nearly impossible to fit in the window channel When you remove the original gaskets, you'll see these "ribs" are non existent . After a little trial and error, I made a jig and trimmed down gaskets from CR Laurence. It was still some work but using Murphy's oil soap and some rubber hammer negotiation, they went together fine.
Pic 1 is the modified gasket fitting in the frame
Pic 2 is the gasket pre-trimming
Pic 3 is my jig for trimming the ribs (tedious but got the job done)
Pic 4 is the best pic i have on my computer of the finished rear window
back together. You can see how well the gasket fits.
I used the modified gasket on the front, rear and all the side windows, as well as the vista views. I haven't tackled the wing windows yet. I'm still on the fence about re-installing them as single panes.
Readingthe earlier posts, I guess others have been able to make the gasket work w/o modification. I hope this post helps if your run into the same problem as I did.