147 and GT are a straight swap. They have splines with one filled in bit to act as a locating point so the wheel stays in position if removed and put back on.
156 is fully splined.
156 and 147/GT wheels 'can' be swapped over, but the process is by significant force to 'cut' the wheel splined section away by forcing it onto the shaft of the recipient car.
Airbag connectors are the same too.
Older cars use different fitting systems that aren't compatible. 159 uses a different air bag connector so even if the wheel could be fitted, the airbag wouldn't work