The chap who owns/runs the Railway Touring Company has ran a few private charters in the past, starting from Kings Lynn, probably near where he lives.
An example was this tour, using 46115 Scots Guardsman, which I think took place on the occasion of his 70th birthday:
http://www.uksteam.info/tours/t09/t0321a.htm
I just happened to be at Ely station that day (hunting diverted HSTs) when the special called in on the return leg.
This would probably be another such occasion. And fare-dos to him as well. He gets to travel round in his own private train, and we all get to see a super locomotive (generally one that does not get around as much as others) and some really old coaches doing what they were built to do.