As a move in the right direction, i have fitted some bracketry and mounted the monitor up high out of the chip path, the brackets stem from the main table frame which is 44x44 structural aluminium, makes it easy to bolt bits on ;)

I also did a facing cut on the bed, here's a video of a bit of it...
https://youtu.be/PSkSn_s8xF8

It was with a 12mm indexable carbide tool at 21000 rpm and 2300mm/min feed, DOC was 0.15mm, just enough to get a cut off the whole face.

The results show the head is a tiny bit off-tram but until i get a decent setup for adjusting it I think it best left where it is, using a DTI it seems the slight ripples made by the tool are about 0.01mm high at the peak,not bad i think as the head was just as i bolted it on!

All things being equal, the results from now on should be 'as good as it gets' for a while at least.