After what has been a pretty rubbish few months for personal reasons, and an absolute manic 6 weeks with only 2 days off due to everybody running events that have been delayed due to a certain global issue, I've found some motivation to progress this over the past few evenings.

This is the current layout iteration, after various sketches-
Click image for larger version.  Name: 211110.png  Views: 265  Size: 302.6 KB  ID: 30640

Or if anybody would like to view the 3D model. this link should work - https://a360.co/3wyt3zD

I'm still not entirely convinced this will be the final layout.
X-axis ballscrews will be in the way of putting legs on the corners, but I can probably shorten them.
Frame is currently all 60x60x5 box section, but I may use lighter section for the cross beams (I've only added two for now, but more will be added)

I need to get the gantry end plates drawn up, and adjust a few dimensions so things will clear/fit.