Hi massimo,
thanks for comment.
According to
http://www.razlib.ru/transport_i_aviacija/aviacija_i_kosmonavtika_2010_04/p2.php it is Su-1:
"
Su-1 after several modifications"
Black propeller blades is a good note. However, there are photos showing their front size in both NMF and black.
However, there was only one Su-1 with several modifications during the trial period so details can vary.
Anyhow that photo shows snow, while the first flight was on June 1941. So it seems the photo shows Su-1 during winter 1940/41 or 41/42. It has red stars on the wings.
This is Su-3, notte the huge air intake at the wing root:
Something similar is visible also at this photo (with retouched turbocompressor):
So this photo really seems to show Su-3 in winter 1942, so also red stars are OK in this case.
There in no star visible on the fuselage of Su-1/Su-3 from the trial period:
So I will remove metal plate behind the propeller, leave NMF front of prop blade and no red stars on wings&fuselage.
Regards,
66misos