When I got my '72 some 16 years ago, the wiper door has one of the corner bolt fittings broken off and missing......so I used some great epoxy to glue a bolt in that position, layered on on good.....still there....
now to simplify the bolt installs, take a dremel and slot the ends of the bolts, so all you need do is take a 1/8" screwdriver, and turn from the open end when the bolts are fully seated, I just take a smidge of RTV to the ends, to secure the bolts from backing out....a simple scrape with a U knife and then unscrew the bolts, nothing but a screwdriver and you fingers, no tools under the door trying to flip them bolt heads....I just used 5/16 dia bolts about a inch long or so, and never did bother with any bushings on the levers....
worked fine for years with the vacuum system, and of course now that it's electric also....
:crutches: