One was done by a member from Temecula CA on his show car. Basically, he removed the bumper, cut a recess in it from the bottom, and bonded in a steel plate some 16" long. The plate was bonded with a type of rubber filler made for fixing urethane noses on late model GM cars. It's compatible with both steel & bumper-rubber. He also went in from the top with flat-head machine screws, then filled the holes. Careful sanding of the cured rubber filler afterwards made the repairs nearly invisible. OEM bumpers are outrageously priced so this may work for you, if you don't want a fiberglas substitute.
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