I run the PS Engineering 1 piece Trans Am wheels on the 350; 15x8 w/4 3/8 bs. Bummer to hear that Phil is out if this is true. There is however Vintage Engineering here in the Bay Area. They do custom magnesium wheels for my application both the TA wheel and the Minilites but expensive! They also do the wheels for Mclarens and Lolas and various Halibrands, so a Cobra wheel may be up their alley. Here's the link;
Magnesium Wheels Trans Am, Indy, Street Rod, Drag
If you thought Phil was expensive, hold on to yuor wallets for a reality check. Someone should give them a call. Another alternative would be Cobra Restorers, Ltd
www.cobrarestorers.com 770 427-0020 they are in Kennesaw, Georgia.
Cheers,
~Earl J