The Nardi Classic I have has a hub attached (looks like HKB). It came off a Toyota Mark II I owned back in the day in Japan. I looked at it this morning and it definitely won't work with the clock spring, which I don't want to remove just to install my Nardi.
Jumped on the HKB Japan site and...
Here is a useful guide on an IS300.
https://www.youtube.com/watch?v=ZV-PIBQczWM
I've installed dozens of wheels over the years and am about to install my old Nardi Classic on my 3rd gen. I'll make sure to take pictures and do a little write up. Getting the horns to work isn't hard after you do...