Bad advice above re Lakenheath and Mildenhall: they will NOT let you go through their ATZ only their wider MATZ.They will however give you an excellent radar service and keep you clear of the heavy metal. Contrary to popular opinion they do speak English.
Couple of weeks ago I could hear Lakenheath well enough to pick out the squawk code and well enough to recognise the pattern of what they were saying, so I was able to give the appropriate responses, but I couldn't pick out most of the actual words. I did gather that they were happy for me to enter their MATZ to play tourists over Ely.
And Duxford will not want you anywhere near their overhead either as they often have display practice on the go.
Every time I've routed directly over the top of Duxford's runway they've been perfectly happy with that and there's been nobody else on frequency. (Obviously if there's something NOTAMed to be going on at Duxford I go some other way.)