Maybe MPS?
Check 50resto.com they have a lot of odds and ends such as this
Crap saw you said painted. They are likely going to be unpainted.
Is it a different shape then what comes on the coupe?
I dont just a weird part. Keep an eye on ebay or i think there are some online mustang salvage sites that sell all parts, but color is not guaranteed.
http://pages.ebay.com/link/?nav=item.view&alt=web&id=391035083631