[Don Plumley]

Nice looking wheel. First big hint: When you do this, unplug the horn relay.

In general, you install the hub adaptor to the car, then the wheel to the adaptor. The six allen head bolts should attach the wheel to the adaptor. (I was able to install the adaptor to the wheel, then the whole assy to the steering column in my car) The ring with the tab is probably a horn contact ring.

Looks like a fun puzzle! Maybe you could turn it into a drinking game?