Need help identifying some wheels

I need some help in identifying a set of 15x8 six lug steel wheels I bought for a 1966 c10 truck. I first thing I noticed was that the center was riveted in instead of welded. I know that normally means pre mid 50's. The second thing is they don't have the outside bosses or ears for a dog dish style center cap, nor do they have any holes or grind marks for the inside clips. The only identification marks I could find is 15x8, and a number 0 stamped on the inside of the band. There is also a circle about the size of a dime with 2 hash marks and a number 8 stamped on them. I would love to find out if they are originals, and if so what they came off of. If they are originals is a 15x6 available? Any info would be great.
Thanks

 

Aftermarket for big tires. They could be modern, or date way back when Dick Cepek was the only guy out there for big tires/wheels

 

Fairly common in the late '60s or early '70s ... used when 1/2 ton Chev/GMC pickups had big campers installed.

 

I put a set of those in 5 lug Ford PU on the back of my old t with Cheaters, worked really well. Looked good.

 

Hey thanks for the info guys. I think I've found a set of 58-59 Apache truck wheels that the are the same style but in a 15X6 width. Thanks again