New steering wheel
 

This is what I have. Hopefully the pics posted

Won't the new wheel and/or hub mount to those 6 flat head allen screws?
Most I have seen have a tapered center shaft with key way in the center, not the through bolt like you show.
But the wheels I have had mount to hub with screw pattern that looks like what you show around the outside.

Never seen a set up like that. I assume you just have take off the nut on the back and pull the bolt out.

There are a few different bolt pattern 5 hole, 6 hole and 8 hole sized hubs.