Everyone keeps asking me, so here they are!
I hope it's OK for me to post these, as I had nothing at all to do with making them. Jay Beckwith kindly sent me the contents of his Ring folder, which includes a load of stuff he has put together - some his own, some by others (Berca's excellent Glen textures are used for asphalt and grass I think)
The sky I am using is Dave Mack's combination of Al Heeley and Simon Stobbart's work. Enjoy!