Hi Nigel,
It looks like you've got yourself a really good project there. I agree about the rear needing changed back, but speaking as someone who's constantly on the lookout for a Mk1 bonnet (and come to think of it, probably also a Mk1 front valance) I can't believe that someone's actually glassed over a pair of Mk1 nostrils to make it look like a Mk2
Go over your chassis and the front beam (especially the shock towers) with a fine tooth comb and don't be afraid to prod really aggressively. Now is the time to find out whether you can start your project with the body on or whether it would be better to take the body off. I really didn't have a choice about going 'body off' because of the state of my chassis, but I'm so glad I did because it's made access to everything mechanical so much easier.
Still think I'm looking at my own Nova in your photos because the colour's so similar!
All the best with your project and you can be assured of lots of help and support from the guys and gals on the Forum.
Alistair