I know of the 1/25 AMT '68 Shelby GT500 kit and it's wheels, but I don't know how good they are:

The 1/24 Monogram '70 Boss 429 Mustang 2'n 1 and 3'n1 kit contains a set of Shelby (at least I think they are) wheels, which are nicely done:

The 1/25 AMT '67 Shelby GT-350 contains yet another variety of Shelby wheels, but again, I haven't seen these in person, so I have no idea if they are accurate:

















