Can you modify the one from ebid and take out the internals and just use it as a functioning cover for a standard cap that will get you past the smog police? Just mount it over a standard modern cap. Then you have the looks you want and are still legal. Or get in touch with Gus at Cleveland Pick A Part and see if he has a totalled Viper he will sell you the cap off. I know he has a few Vipers there. He usually lists engines in the "for sale" section.
Just my .02. Good luck.
