[Mirek Wawrzynski]

Deeply sorry, but I think you are for a long time ago have undrestanand and more then well know, that one thing is claimed and credited victory (by own units commanders and superiors). Second thing is real damage - destruction of plane.
Of course in my estimation I do not count credited victores as a total, and any real loss for enemy side. In reality you should dived claimed and credited vicores by 3-4 and sometiems even more (in Winter War about 7-8 factor) to get real losses on oposite side.

I exactly know real loss of FAF (total losses+ damaged), JAAF over Chachyn-Gol, about Polish Losses in IX 1939, some victories over China (about 80). There were a few air clashes over Rumiania in summer 1940 (if I right rember Sovitet fighters shot down 1xPZL P.7 and 1 x IAR-37 or 39)

So in above calculatin I only think about claimed + credited Soviet victories, but not about real losses done to oposite side. These are two very separate things.

Regards,
mw

BTW
FAF's total losses of course were much higher (destroyed + damaged)then 53. The last figure is if I am right remeber only shot down by Sovite (in air combat and A/A) and total losses excluding damaged and later repaired.