I'm glad to be able to suggest that you look at these sites - but only after you've had a good look round my pages!
Miniatura is held twice a year in the NEC, Birmingham. Dates are on my Fairs page and you'll find them, of course, on their own site.
Warners Group run exhibitions and they are responsible for the Dolls House shows at York Race Course in June and November each year.
Miniaturists - please let me know if you want a link establshing for your site.