I found this on eBay:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=10076&item=2450522 902

It's a set of Marchals, but they have yellow lenses. Does anyone know why they would have yellow lenses?

The Marchal lights where used on other cars before they where picked for the Shelby & GT/CS. Those cars used them for many different applications, I believe the yellow lenses where used for driving/racing in fog. What ever the reason, they are incorrect for the GT/CS, but the housings are still correct if they are the 656's. You will also see clear lenses with yellow bulbs.
Doug

Thanks. I emailed the guy and he said that they might've been put on since the lights were too bright.

European vehicles often came standard with yellow lenses. Marchal was a very popular manufacturer of lights in the 50's thru the 70's in Europe.

Robert

Be sure they are the 656 as the 653 (the model prior) will have a part number on the eyebrow which is incorrect.

Good luck.