Just thought I would post this as it arrived yesterday and maybe other owners could be thinking of the same.
Got the dash from Custom Instrument Panels in the US. Mac is the owner I spoke to directly and he makes them up for each customer.
I think it looks great and looking forward to fitting it. Looks well made. Pic of the rear is a two connector option but of course on the 1975 20 its a single connector. I ordered two but the 2 connector one is for someone else in the UK.
Will post again when its all connected and working.
Link below if anyone else in interested.
http://www.custominstrumentpanels.com/chevy.htm