Hi, I've just received a mail on this topic by Alex Ruchkovsky.
He made me note how strange is the 3 of 93. He suggests that it could be a 5 modified into a 3.
Imho, it is fully repainted:it doesn't use the rounded font of the 9, from the factory, and appears rather angular on its lower part, while we can suppose that the bottom of the 9 is rounded as its top.
At first I was in doubt that what I see on profiles was an E (Cyrillic alphabet shows three different characters related to western E), but Alex made me clear that :
... yellow cylillic E (Э) on the fin as the first letter of the regiment's honor name "Elbingskiy", related to the town of Elbing in East Prussia, now Elblong in Poland...
Another interesting thing: he was told by Bykov that the emblem of 156 IAP were only two red stripes, not three.
Again, what I think to see on this photo are two thick red lines above the stabilizators, and one thin below the elevator, on the rudder only.
I wonder if the La-7 logo was preserved on the nose, aside the medal, as it was preserved on the rudder.
Alex hasn't further images of tails of this unit.
Some photos of similar planes of 156 IAP can be found here,
http://www.soviet-aces-1936-53.ru/abc/zh/zelynkin.htm, but aren't decisive. Strangely, here Bykov has drawn a profile with 3 red stripes.
Regards
Massimo