Hmmmm....

I have followed your advice and reduced the values to:

R-0,8,  G 0,4 and B 0,4 with a scale of 0,015 - with the desaturated defuse map linked into the channels (like in my latest post
R--0,48, G0,18 and B 0,11 with a scale of 0,015 - without a texture linked in. 

Both results are good and more or less equivalent.

The interesting bit is that the values of R-2, G-1 and B-1 in my original texture are some I got from a previous discussion in the R'osity forum, and I've seen them used in various textures I have come across.

But for Dawn 2, I'll be following your light and go with the lower values. hborre - thank you again!