Yes Terry the Sotar has an adjustable setting. It acts as a stop as you pull the trigger back, and can be set from completely closed to completely open. I plan to do a lot of practice first.
I think I have decided what I'm going to do as far as the mottling is concerned. Below is the only actual photo of the aircraft, and various profiles of it, supplied my members of this forum for which I am very grateful. As you can see there is a wide variation in the interpretation of the mottling in the various profiles, none of which I believe is totally correct. After studying the photo I've decided to combine different areas of the profiles to make what I believe is the closest interpretation of the photo.
For the basic mottling I am going to try to replicate what is shown in the first and third profile. I believe this looks closest to the photo.
For the Stab over-painting mottling I am going to use profiles 1 and 2. the other profiles look much too heavy when compared with the photo.
In 2 of the profiles the Balkenkreuz has been over-painted with mottling. The photo seems to show this although I'm not sure, but I'm going with it, I'll use the 2nd profile as a basis as it's not as heavy.
The spinner is a lighter color in the photo so I'm going with white as shown in profile 3.
And lastly the yellow distemper paint on the nose looks rather worn in the photo so I will try to replicate how it's shown on profile 3. I've given this a lot of thought, and what I'm going to try is to do the mottling on the yellow areas of the nose and rudder with black paint, then put a light cote of yellow over it so the shadow of the mottling shows through, then do a little weathering over the top. If this doesn't work I can always fall back to my original plan of heavy weathering.