When you are attaching moon discs to aluminum wheels its not a good idea to weld the 3 mounting tabs to the wheels. As it can change the temper of the aluminum wheel, making it unsafe to use at speed.
Most racers will use 6 ( at a minimum) machine screws to hold moon discs to the aluminum wheels. While this works well, it makes it much more difficult to easily and quickly check tire pressure and lug nut torque in between runs.
I came up with the adapter ring that you can drill and screw to the wheels ( or use your already drilled holes, as to why they are a blank). Once ring is attached you can use standard 1/4 turn fasteners to attach moon discs to your wheels. No welding, not damaging temper of the aluminum wheels.
Sold in pairs - kit for 2 wheels
laser cut in 14 gauge aluminum for 15” wheels
Kit includes - 2 (two) adapter rings, 6 (six) 1/4 turn retention springs, and 12 ( twelve) pop rivets for attaching springs to adapters