New Oldham couplings for the Z and Y axis have been fitted. The X axis has not been replaced but it has also never been broken. We have the bits to fit the X axis, we can do it next round of breakages :p Slop and backlash have been greatly reduced, and the machine sounds smoother now.
I think we should not use the previous vice for gripping and instead get a new precision one. The old vice was too big, heavy and did not have parallel jaws when tightened. Recommended milling vices seem to use a totally different mechanism to ensure the jaws stay parallel under pressure, for example http://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices