Sun Visor

Starting work on the interior of my '57 Retract and was looking at replacing the original vinyl heat seamed sun visors. As far as I can tell, no one makes a replacement. I've found someone who can rebuild them. My question has to do with their shape. Instead of being flat, they are curved. Is this the original design? Was it done this way so when the top is down and the visors are up that it forces the air up over the driver?

These are what I used on my Skyliner, not sure if there correct but they look good.
http://www.ebay.com/itm/1957-1958-57...dWHC7E&vxp=mtr

you are correct , the original Coved white visor With no support pin (or with one ) are dynosaurs