Thank you for all the comments.
I was merely looking for stock! Thorn is a business and it currently does not have frames to sell. uumm....
I know that they offer many frame types, in many sizes and in many colours, all with minimum orders qualities to think about, but I think it is true that -
* most frame designs are up-to-date, audax, mercury, club tour and nomad.
* not all colours would be necessary, 1 or 2 would be fine.
I would have bought not only the frame, but specced up the whole bike - I've stopped checking and will now look at other brands. Shame, because I quite fancied (another) one.