As I said, there is no correct anything for fog lights on a 64.5, wiring or whatever. The car in the auction had the lights added. I would never drill holes through the rad support for this. Keep it something easily reversible, you may get tired of folks asking about why you installed them and you may want to take them off later.
If I was judging the car in a concours event, I would deduct points for them on a 64.5. Your goal may not be to show the car, but just stating a matter of fact of how they could be perceived at that level.
A more period-correct fog-light setup would be the style that bolts to the front bumper, but very utilitarian by design and not much on looks.