Richard
Good luck with your most worthwhile project. It's good to see that you are approaching it in such a thorough way, all credit to you.
As you are asking for advice, I hope you won't mind my warning against the common mistake of painting the undersides Light Aircraft Grey, instead of the correct silver/aluminium, as mentioned by Kieron Kirk?
Light Aircraft Grey was introduced long after your Hunter's flying career was over. There are a few preserved early Hunters around, including one that used to be at Hendon, that are painted that way.
Just be careful of anyone producing the final version of the Hunter's Colour Scheme Chart (or whatever it's called) and trying to tell you that Grey is the colour.
Anorak off
HL