This winter I've been rebuilding the interior of my car.
One item I could not find any information on at all were the mounting dimensions of the RS Mach Steering wheel. I believe in period this was a competition option, with the thicker wheel material and 380mm diameter often seen on the s30 and Hako Skylines.
It seems the RS Mach wheel mounts more like the JDM s30 wheel compared to the deeper dish of the USDM wheel. Potentially I may machine a spacer to move the wheel further out but will see when I get everything back together. I know for the JDM s30 wheels it is popular to modify the turn signal stalk to account for the difference in wheel depth. I am also around 6' tall so also likely dimensionally different than the typical JDM person in period.
Hopefully this helps someone. There is plenty of information out there for Checkman, Nardi, JDM s30 types, etc. types but nothing on this item.