Ok, those posts were just painfull to read...
Now, back to steering wheel installs.
First question - which hub are you using?
I did my install using the eBay hub (HKB or whatever it is).
Pics here -
http://public.fotki.com/relittle/miata/sparcoring/
You take the hub apart, drill two new holes for the pegs on the clock spring and bolt it all together.
The best install article for the eBay hub is on the pointy site -
http://forum.miata.net/vb/showthread.php?t=172922
It has everything documented nicely.
On a side not, wiring in a seperate horn may not be legal in your area, it isn't in North Carolina. The horn button has to function in its factory location, if the factory horn button was on the steering wheel, it has to stay on the steering wheel.