Right!
Fourth try on the Bradley with smoking cheeses, and I think I've now figured it out.
I decided that Double Gloucester, Brie, and Camembert are all 'pants'. Also, smoking for under 2.5 hours won't cut the mustard. So I now have a narrower selection of cheeses, and a better idea of how long to smoke.
I think smoking for 3-4 hours is about right. And the best cheeses are semi-hard to hard cheeses.
I just ran another batch, and clockwise from top left, we have:-
Mild Dutch Gouda (cheap, but cheerful)
Vintage Strong Canadian Cheddar (See Note 1. Below)
Vintage Matured Dutch Gouda (See Note 2. Below)
Mild Dutch Gouda
Mild Dutch Gouda
English Cheddar (strong, but not farmhouse)
More Vintage Canadian Cheddar
Vintage Spanish Manchego (sheeps' milk) cheese (See Note 3 below)
I have high expectations this time. I'm probably going to have to freeze a lot of it, but three or four pieces are earmarked for friends who have now learned that I do my own smoking. Strange, I've only owned it for about 6 weeks! Word gets around.

Notes:
1. Canada makes exceptional Cheddar cheese, some of the best in the World, which is almost as good as the best English Cheddar (and I am saying this as an Englishman, so high praise indeed!). I wait with anticipation to see how it 'smokes'.
2. The Vintage Gouda is not something you are going to find outside very expensive cheese stores, and mainly ones in NW Europe. Actually, this is an exceptional cheese on its own, and I'm going to go back to the store to get some more of it (but not smoke it this time) - If any Brits are watching, I found it in John Lewis, Oxford St - but very expensive even so.
3. This is Spain's most famous Cheese export. It is a sheep's milk cheese and something rather special in my humble opinion. I personally love it, and it has the right texture to be smoked. This particular one was a premium one from an expensive food store in London (John Lewis Food Hall for the Brits!). I think that this will be the best of the lot (unless the Gouda beats it).