i saw a set at the NATS but cant seem to find them.
they are sort of like this only flat just covering the hub on the rear wheel. chrome held on by the nuts
where can i get them?

They are called hub covers, I can find bullet ones at Speedway, but not flat ones.

http://www.speedwaymotors.com/Search?query=hub+covers

a million years ago, i believe those were called "spider caps". some were attached over the wheel center and the nuts retained the covers and the wheel at the same time, while a different version was installed before the wheel was put on the studs, covering the axle ends [center], retained by the wheel using the nuts in the usual way. those type were used with a wheel that had a bigger center diameter than the axle register, which allowed the covers to be over the axle center and pass through the wheel opening, giving the appearance of a chromed axle through the wheel's center opening. those were flat instead of having a cone shape. think center caps that fit through aftermarket wheels, only being flat instead of cone shaped.

Not too sure how that would work with a hubcentric wheel like a stock steelie.

those caps that were retained behind the wheel wouldn't work with a hubcentric wheel. they needed a bigger hole like an aftermarket chrome steel slot or some chrome reversed wheels had, or if your stock wheel was lugcentric. i remember the local "western auto" store had those caps in both versions next to the bins filled with chrome wheel nuts. i can't recall who made them though. my cousin had a '58 buick century with flat caps in the rear, cone caps in the front, chrome lugnuts, and chrome trim rings on black steel wheels with twin 3/8"[i think] whitewalls. the car was a bright gold and all the chrome work was very nice. that wheel/tire combo looked good on that car.