Dave,
AZ offers three plate options for classic, historic and street rod. There does not appear to be an option for using a "vintage" plate. Are you in AZ or FL ? It does not appear to be offered in FL either.
http://www.azdot.gov/mvd/vehicle/mvdplate.asp
http://www.hsmv.state.fl.us/html/titlinf.html
obviously websites may not be current or have all info. I'd check with a local office.