Y'all could use my trick from the '90s. You remove the front quarter glass and fabricate replacements from Lucite, then BOLT the mirrors to them. If they need minor shimming to correct the angles, hand-contoured wood spacers are also easy to make from 2x6s; paint to match.
The removed glass is used with Mom's oven to get the plastic curvature perfect. 150-160F for about 15 minutes causes the plastic to sag around the glass, which is totally unhurt by such heat. Then you trim to fit. I found the hard way that one should use sun-resistent Lucite or it crazes after a year or so. Still working with my Dodge Omni mirrors.
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