Mine are rectangular on my 70. But the DC cowl lacing with round clips fit perfectly. I made the same mistake of ordering that *** piece of junk. It didn't fit right, had to trim it, and when you closed the hood it stuck out the top of the hood! I have found them(DC) to have very good quality rubber items.
If your gonna do it, do it right. Yes, NOS is the way to go, but you can't always find it.

 

I bought mine from *** a couple of years ago. The clips fit the holes fine ('69 F100) altho' the lacing itself had to be trimmed in length.

Ben

 

Does the horizontal leg go on the top of bottom when attaching to the cowl?

 

With it on top upwards like a 7

 

Geez this must have come out of Sleeping Hollow of 2003