Stig,
When it comes to losses, the VVS documents are pretty detailed. From what I have seen, they seem to be even more detailed than the German i.e. you can find the details like "three strikes in the left wing, six in the fuselage, one in the cockpit". You can find references like minor damage, fixed in the regiment within 24 hours or 48 hours, damage required the plane to be sent for general repairs etc. You have documents from various levels - regiment, group/division, army etc. How it all looked can be seen in documents which are made public at pamyat naroda web portal, but this is just a drop in the ocean. Basically, everything was recorded but one needs to spend months in Podolsk to find it
In my opinion, the greatest problem is the sheer size of VVS, as you can often come upon dozens of regiments and auxiliary units fighting on one particular section of the front.
Denes,
not sure about that, but in general, VVS fighters overclaimed heavily, I'd say much more than their Luftwaffe counterparts. You could check some articles at warsport.ru with the help of google translate. I eagerly expect to see the work about Kuban battles in the spring of 1943 which is prepared by a dear friend and a member of this forum Andrey Kuznetsov. It will answer many questions which some of us thought will remain undisclosed forever...
Cheers,
Boris