These appear to be like an ETII, steel rim welded to a cast aluminum center section. These are not American Magnesium Torque Thrusts. There were a lot of two piece wheels like these in the 60's. Could be Appliance? Also appear to be uni-lug. Have been racing with "R model" wheels for 40 years, so I'm pretty sure "R model" wheels were /are American Magnesium.