A slight bit off-topic but close enough for government work and worth a look…
An episode of “Midsomer Murders” (a BBC2 (I think) mystery series) featured a model village that looked like a real attraction to me, so I pursued it. Turns out that the UK is known for them and that there are quite a few.
I grew up a few miles from Bekonscot and as a child is was one of my very favorite places to visit. It really is a marvelous place to go as a kid. I have many fond memories of the place. A few years back, when visiting family in the UK, I took my two train-nut American sons and I was delighted to find that the place has really been kept up and expanded. I enjoyed it just as much as an adult as I did as a kid. There is a ton of stuff on YouTube, this being a good one http://www.youtube.com/watch?v=HMsJ_P6d-zg
Pecorama is down in Devon, so quite out of the way, unless you are going to that part of the UK anyway. My parents currently live in Somerset, so Pecorama is not too far from them. I really enjoyed it. the gardens and the views from the cliff top location are really very nice. The indoor demonstration layouts are very good as well. My assesment, if you are in the area great, but I would not trek all the way from London to see it. You don’t get to visit the factory, which is a shame, as I would have rather liked to see that part of the operation.
York on the other hand is one of the best railway museums in the World IMO. I will be in the UK in early June and am planning to take my boys on this trip. They really want to see The Mallard in person.
The UK is a really great place to visit for the railfan. There are a lot of live steam preservation rails and there always seems to be a trainshow on when I am over. Just look at this map! http://www.heritagerailways.com/Visits_Map.php
“Midsomer Murders” is a great British TV Series lasting over 10 years that has footage from many small English Villages. Very enjoyable and I’ve watched all of the episodes featuring John Nettles as DI Tom Barnaby. Many episodes have interesting views of British trains, including some old steam engines.
British model train meets also feature some exquisite exhibition layouts duplicating specific landscapes and towns. So try to visit some on your trip there. You can find listings on line at various sites like this: https://www.model-railways-live.co.uk/Diary-Dates/