Tommy, did you say you would be in Oxford or Cambridge later in the year?
If Oxford make sure to play Southfield (Colt). You already know Frilford Heath. Others that are decent and not far away include Goring and Streatley, Henley (on Thames), Tadmarton Heath (Banbury) and Huntercombe (which I imagine you've played).
If Cambridge make sure to play Royal Worlington, the best 9-hole course in the country, Gog Magog on the southern outskirts of Cambridge, I could get you a game at Sandy Lodge. I think you'd like Thetford, too.
Mark.