Stallion, many thanks for the offer of photos. No hurry for them as I've got to learn gmax first...
That's just as well, as I didn't get a chance to take any today! We ran out of time for a lot of things, so we are planning to go back next week (makes a change to walk/shop somewhere other than Leicester). If the weather's okay I'll take some then. We'll go earlier so we have more time! 1.5 hours on the bus each way...

I've done a spot of basic modelling in gmax myself some time ago, so I'll try to get some photos along the length that are all taken square on to the walls. Large photos taken at a slight angle can always be stretched into the correct shape in a graphics program later though.