After leaving everything to set over a couple of days I was able to do another mockup of how the bike will be, I'm now a lot more happy with the chainstay (429mm) and was able to set the BB height with a block of foam.
A have also checked the amount of travel possible - and I think it would be able to get about 135 without touching the seattube
The wheel seems to be about 1-2mm of center - but this isn't to much of an issue- my hardtail is about 3mm off!
To fit a front derailleur I have had to make a aluminium plate for a direct mount front mech - using the dimensions from the drawing below
I'm setting the seatstay in situ so to make sure it is 100% aligned, but this means I'll have to do the rest of the finishing layup tomorrow.