No problem on mounting a front plate on a 57 Chevrolet or any 50’s to possibly late 80’s American cars. The fronts were designed for a plate holder and to me it looks fine. It was only on the sportier models that it sometimes looked out of place. Gen 4 GM F bodies for one. C4 /C5 Corvettes had the cut out for a plate for those states that required one, and a cover for those that didn’t.
front plates also never looked right on E-Types, hence the stick on lettering type of plate on the bonnet.