I have a set of original "Powered by FORD" 289 valve covers for sale on eBay -
http://cgi.ebay.com/ebaymotors/ws/eB...m=200383734025
These came off the '66 engine in my '65 convertible. I had them blasted and primed by a local restoration shop. All they need now is a coat of Ford Blue paint to look like they're right out of the factory.
It's my understanding that these covers would also be correct on some 1967 and 1968 289s, but I don't know that for sure.
Any questions just send me a PM. Thanks for looking!