Thanks for your comments Rob. I have been playing around with layer masking off and on now for a few days, and eventually got an image to put up. Although I couldn't follow the link right through with my Photoshop program Version 11, the end result is an improvement on the first in this thread.
This image is from 15 x 5 minutes and 21 x 10 seconds exposures.
Comments welcome.
http://i638.photobucket.com/albums/u...rstGDFinal.jpg