Welcome to FGRV Roberta!
You don't show any pictures of the front here or in the registry. Assuming your front window was like your rear window, it is merely a sheet of plexiglass which flexes enough to follow the body.
Although some window sizes and gasket are available from Scamp
almost any auto window shop should be able to do the work for you. If you are handy, I'd suggest sourcing the gasket locally or get it from Scamp
and cut a piece of plexiglass to fit. There are lots of pointers here on how to do it.
Kevin here made a video of how to do it, but he uses the gasket backwards from original. Your choice I guess.