Went and had a look at this today. Saw a lovely selection of Steve's work and had a good chat with Jeff the owner. He said that there were about 90 pages of art which he was displaying on behalf of Steve's family. It's not a massive space so not all the work is on the wall, some is in folders. If you want to buy any of his 2000AD pages you're out of luck though as those ones aren't for sale.
Well worth the trip down from Nottingham and I would recommend the trip if you can get there.