If it's helpful, scissor jack from a Mark III golf fits into the jacking mount thing under the car - I've used that a couple of times on my Z (our other car is a MK3). Loads of them in the breakers usually.
As I remember (probably a yr since I've done it mind...), it kind of sits on the edge of the jacking point, which is square. So it's not quite the intended fit - but it definitely fit, was secure/stable, and didn't seem to be taking the weight anywhere it shouldn't be. (I used to have a KA and jacked it up in the wrong place once and stuff bent... so paranoid about this last bit!)