[w21055]

Deep sixes have a deeper lip at the end of the pedals, flat sixes are just that, flat, so instead of the pedal stopping flat it sorta curves into the lip. Big difference in price. The 7R wheel you posted a while back is what the pedals look like on a deep 6. Some Deep sixes have a heart shaped hole at the valve stem and the later ones do not.

On your other question, H4's will fit, I just put them on my 68. H1's are correct for the year, but about twice the price.

Phillip