Thank you to everyone who commented on the hubcap photo on the HVA website and the HVA's Facebook page.
The hubcap in the photo belongs to 1957 Rambler Rebel made by AMC.
The 1957 Rambler Rebel, was a mid-sized "muscle car" built by American Motors Corporation (AMC). After the Nash and Hudson names were discontinued in 1957 the Rambler name was applied to AMC cars until 1969. AMC continued building cars until 1987 when the Chrysler Corporation took over.
And the winner of the contest – George Anderson from Chandler, AZ!
For guessing correctly George Anderson will receive a free HVA ballcap. The same cap is available here, in the online store.