Thanks again for the replies.
Initially I will probably be based in the Paddington/Bayswater area of London, but if there is time I'm also hoping to check out a few places in Suffolk, Surrey and Warwickshire where some of my ancestors came from.
Yes, I guess that is a fair slab of the countryside, but remember, I come from a country where we are used to great distances (but cheaper petrol).
To those who've made offers - expect some PMs shortly so we can work out what might be mutually convenient. Thanks, all.