Re: wheels and tires for a 69 RS
You can buy reproduction tires that look and perform like the originals.
In 69, the Z came with E7015 bias ply tires.
Either Firestone Sports Car 200, or
Goodyear, Wide Tread Custom GT
Goodyear did not make a sports car 200.
I have a set of the Firestone Sports Cart 200's mounted on my original YH ralley wheels. They ride and handle horribly. That is why they are on the wall in the garage. I run modern radials on a set of FW ralley wheels for everyday driving. The FW wheel is
within 1/4 inch of the same off-set, but much cheaper.
If you like the size of your orange ralley wheels, you can strip and paint them argent silver to make them look original. Would be a lot cheaper. BFG Radial TA is a good all around choice that is ALMOST period correct.
And yes, there are some old school mags. Stay away from unilugs. Most of them come in 16, 17 and 18 (or even bigger) but many are still available in 15. Personally, if I were going old school, I would look for a vintage set of wheels.
BTW, yes there were some orange wheels. Many of the cars that did not come with ralley wheels got steel wheels painted body color. So, if you bought an orange Camaro, it could have come with orange wheels and the "dog dish" cheapie hubcaps.