those round side marker lamps

While searching for an am/fm radio at a swap meet the guy next to me was asking about round side markers. The seller had 2 of the flat chrome type but the buyer wanted the ones with the slight angle. Seller says something about the angle ones being more rare. I didn't even know there were 2 types.
So my question is what cars had the angled chrome bezel fixtures and/or how rare are they ?