1st Gen slide rear side slide windows

[xcuzzi]

Does anyone have a fix for the back seat slide windows that don't want to close?  I have removed the frame and windows and had them tinted. I repaired rust on the "L" metal and reattached the frame using buytl rubber in a tube from automotive glass shop, and cleaned the gasket that appears in good shape. It seems like the gasket has "shrunk" over the years and has made the window hard to close.  I have considered cutting the gasket some how to make room for the window to close but I am sure these gaskets are really hard to find/replace if that doesn't work or leaks after I am done. Has anyone had any luck fixing these things?