As per my post on the JAF homologation papers topic, the JAF GT010/ FIA 3023 fiches do NOT show anything to do with 15" diameter wheels. They show the Nissan Sports Option / Junsei Race Option 14" x 8j and 14" x 10j Magnesium KS 8-spokes that were intended to be used with the 432-R type overfenders, but no 15" diameter option.
So where is this "Official factory documentation" that shows optional 15" x 7J wheels?
Wasn't there a thing called the Zapper in the USA, it had bgger rims.
As far as going to a 15" here in Aus, they have this ruling called "plus 1" which refers to an allowance to go up 1" from stock diameter, and out 1" from stock width, that solves the 15x7.
Then the authourities require thatwheel track does not alter from stock, so any wider type rims mst be equal increase both inside and out.
The JAF Homologation papers, f one was to photocopy the front page, and only the page showing the wider 8 and 10" rims, as part of a "nissan factory documentation" one can try to attempt to have their 8,9 or 10" wide rims, with a bigger 15" diameter, accepted by Transport Engineering, here in Australia.
I think the Zapper was an "end f model" attempt to clear last stocks, it had garish decals on it.