This is a military training film made in the 1960s. Once you get beyond the old style voices and video production techniques (some of it pretty funny), you'll find a lot of good information on working with and maintaining Plexiglas canopies, windows, and windscreens.
Some techniques discussed:
cutting and sawing Plexiglas
drilling
thermal expansion
attachments to metal frames
forming with molds
materials caustic to Plexiglas
buffing and polishing to remove scratches
repairing cracked areas and patching
prevention of crazing