DieselTime

Hey all,
Kind of a weird question but I'm looking at a flat-bottom steering wheel for my R34 and I've found one for the S15 that's considerably cheaper. The part in question is only the surround, with the OEM "pad" for lack of a better word making up the centre, as you can see in this pic:
https://www.redlinegoods.com/images/...omwheel-01.jpg
My question is, are the pads from the S15 and R34 interchangeable? They seem about the same size and shape, and I've heard of guys putting S15 wheels in their R34s, so I know the surround at least will fit, but if I can help it I'd rather not have to buy an OEM S15 wheel on top of the aftermarket surround.
Again, kind of a convoluted question, but any help'd be appreciated.