I worked in the tire and wheel business in the mid 70's. There was an Ansen knockoff wheel that had oval slots for the lugs. It used standard shank type lugs and washers, not Uni-lug. If the lug holes are nicely formed ovals from the center outward these are the ones. Ansen Sprint II used round Uni-lug washers and were polished. ET IV used oval Uni-lug washers and were polished. Ansen Sprint I and Fenton were not Uni- lug, and machine finished. What brand is cast into the back of the wheel. My bet is they are 8 1/2" wide. Measure between the beads, not outside.
Doug