Paul what thickness is the bracket on top of the rear beam?  Did you
plan to do a detail drawing of it?   Also,  I assume the bushing is a
Barry Control.  Do you have a part number?    Jerry

3/8th inch. Part number 2001. Here are the drawings.

Maybe you are talking about the steel bracket with the
two ears sticking straight up. Make it out of .065 thick
4130 with long 1/4 inch mounting bolts.