I've been checking out the machine some more. Mainly tramming today.

I found that it was out a little.

Adjusting the spindle mount to get it perpendicluar to x axis (left/right) is pretty easy, but is there a prefered method to adjust the other direction?

My tramming arm is 100mm long, so over 200mm I am seeing 0.2mm 'nod' forwards. I was thinking I just need some very thin shim stock under the bottom bolts of the spindle mount?