Ahhhhh,... now I understand.
I took delivery of my 1200 parts book today, & in conjunction with this thread, i now realise that i do not have a 1200 GX steering wheel, i have a 1200 coupe option steering wheel instead. I had wrongly assumed that there were only two diferent steering wheels for the 1200, when in fact there are three.

The wheel illustrated above is basicly the Datsun 1000 coupe option wheel with a diferent horn button & a diferent adapter to the column. See my photo's in my photo album for a comparison.

The 1200 wheel in the heading photo looks to be the coupe option wheel also. Both my 1200 coupe option wheel, & the one in the photo are missing the simulated artificial imitation pads in the spokes, & this is a common thing. The parts book shows oval holes in the spokes, but both of mine have tapered slots in the spokes, the same as the illustrated example above.
The part numbers for the pads, & the horn mechanism parts are the same for the 1000 & 1200 coupe option wheels, & while the bare wheel is not listed separately, i would bet real money that these are the same also.

The genuine GX wheel is a derivative of this style, with black spokes, no spoke pads, & the slots in these spokes have a divider piece, which means that each spoke has two shorter slots/ holes instead of one longer hole. I like the coupe option wheels better, & by comparicon, the bulbous horn buttons on the 1200 steering wheels wheels suck. The smaller 1000 button really suits the style much better.

Thanks for the info Chris.