Chuk - I spent much of the day today with fellow Bolter KCMongo here in the Kansas City metro area, who is a long time supplier of most things old Chevy and GMC truck.

I asked him if he had any wheels that would fill your need and he showed me several in his parts yard that we visited this afternoon.
I know it's a fair distance from you, and getting one to you would involve a pallet and associated shipping, but if you're interested, give him a call at (816) 265-1462.