With thanks to @iceton1975 and @volstretch, I've had a pretty successful week or so of parts gathering.
@volstretch sorted me out with grey V70R seats and door trims.
@iceton1975 got my rear brakes organised as I'm going to use P2 S60R/V70R rear brakes.
On a sadder note, the more I do my maths, the more I think that the Fifteen52 tarmac wheels from the Focus are just a bit wide with too aggressive of an offset. I dont think 18x8.5 and ET40 is going to work. I want to run a 225/35/18 and I can't stand even the slightest stretching of tyres.
18x8 and ET42-48 would likely be best.
Anyhoo, the Vocus will go to a new home in a couple of weeks so I'll look at that again soon.