Welcome to the Shop. I know what you mean about the front plate. All I have are the wide slots, but no bracket. I think you could just bolt the plate, with an appropriate MB frame, through those slots, but I have never tried. Even though we are required to display both plates here in CA, I haven't tried to locate a sutable fixture yet. Someday, maybe I will, until then the front plate resides in the trunk.
73 280 SEL 4.5