Hi Massimo,
thank you for posting my articles.
In the meantime I browsed through
https://www.vif2ne.org/nvi/forum/0/0.htm (unfortunately it does not give a link to the particular post) and I found there an interesting discussion from 2012 about this colorful Yak-1b. It is in Russian language, here are some interesting info translated to English.
EDIT: Regarding Pokrovskiy, it is reliably known that he was transferred from the 2 giap of the Northern Fleet Air Force in May 1943 to a new duty station, unfortunately there is no exact information yet where exactly. Presumably at first to the VMAU (Военно-морское авиационное училище - school for military naval aviators) and then to the Black Sea Fleet Air Force.
From interview with V.A. Tikhomirov:
"In May 1943 I was promoted to junior lieutenant, and in the same month I was sent to the flight commander course, where I took a course in flight and combat use on a Yak-1 aircraft. There were three squadrons in the (flight commanders) course: fighter squadrons (commander - Hero of the Soviet Union Pokrovskiy), attack squadron (commander - Hero of the Soviet Union Stepanyan) and bombers (commander - Nikolaev)."Yak-1 is Pojkrovskiy's plane from the time when he was already transferred from Northern Fleet to the Black Sea Fleet Air Force (unit not known), also at the end of the war. It is doubtful that the painter/artist traveled like that, although anything can be...
Pilot in the Yak-1 cockpit is (allegedly) Pokrovskiy.
Il-2 plane belongs to 2 HSU Nelson Stepanyan, Baltics, 1945 (?)
Plane painted in the similar style but not related to the Yak-1 and Il-2 from above:
But the Yak-1 and Pokrovskiy are two things not compatible with the place and time during period of his stay in the regiments. Allegedly first-hand information is that Pokrovskiy was filmed near this plane somewhere in Bulgaria. After completed operations in Romania the parts of the Black Sea Fleet Air Force were based in Bulgaria - 6 giap and others. The defective plane stood at the edge of the airfield (in the photo you can see, despite retouching, removed water radiator and missing cockpit canopy) and such a painted plane attracted attention of the photographer...
Spepanyan's plane on the photo (in other occasion) is without a machine gun in the gunner cockpit.
From these two facts and Tikhomirov's memories the assumption was born that these planes were painted at one place - at the flight commander course. From the point of view of the formal logic such a colorful painting could have taken place on the planes in the rear regiments, but in active units?
Regards,
66misos