After some long processing sessions I managed to add on the extra 5hrs of data I gathered over New Years - essentially doubling what I originally had. Below you'll see small before (left) and after shots. Better depth and detail with less noise reduction but I think I've left enough "grain" to keep it looking natural.
Small:
http://www.pbase.com/gailmarc/image/131130926/large
Large (use browser zoom to 50% to see full screen)
http://www.pbase.com/gailmarc/image/131130926/original
Cheers, Marcus