Getting a bit confused now...but thankyou again.
The current blade in use has a bad weld so it has a bit of a hump along its spine.Accounting for that the blade appears to stay perfectly in place on the wheels under rotation.
I also have again hung the teeth off the tyre as Centauro suggest.
So again I will ask how will any east/west alignment issues of the flywheels manifest when cutting.

So we're trying to measure if the motor shaft and top wheel shaft are lying in the same planes in both x and y axes but the x axis specifically, and how to do this in straightforward way as only one of them is adjustable left to right.
I did put a dial guage on both wheels and each seemed to have a variance of about 5/100 mm,given the vagaries of a cast iron surface.
But no comparison to each other.
It would seem that to be relevant any variation needs to be measured at the horizontal mid line.
Given the relatively small diameters of the shafts this feels difficult to achieve in a meaningful way in a woodshop.
If I set the saw level and then shot a vertical laser line I'd possibly pick up some variation?

Using the 25mm blade and cranking up the tension a bit more has helped with the blade wandering.Currently wanting to rip 300mm.
The most significant issue now is the work piece drifting off the fence.
I've tried the free hand cut allowing the blade to take its course and then setting the fence to that but no joy there...?
Thankyou to all who bother to read this.