[Franek Grabowski]

Andreas
You have almost fully answered your own questions.
Yes, the main problem is lack of resources. I have no doubt, that most of losses were recorded some way, but having a fraction of original documents, we are unable to verify most of existing data, not to mention filling any possible gaps. More, we are unable to use all of documents, as as we know eg. personnel records are not accessible to researchers. Of course, you are right, that it is possible to look for obituaries and death notices, but the problem is with access to these data as well as with numbers involved, combined with limited information then released to the public. More, I expect most of possible gaps are aircraft with various degree of damage and not involving human losses. How many of them were not recorded, how many aircraft of older types were written off despite minor level of damage, how many aircraft were reassessed to another degree of damage?
You say that "five" losses is not enough to prove the point. All I can say is that I have found those "five" losses without any deep research into the Luftwaffe. I suppose that with a more complex research you can multiply those "five", but do not ask me about the factor. Still, there is no reason to avoid discussion on those "five" cases, as well as Galland's loss estimates. Also, please note, that talking about reasonable 10% of total losses, we can get a totally different percentage in individual cases.
Finally, talking about Allied records, do not be silly! Of course, there was some overclaim, but this is a completely different matter. Let's talk about small skirmishes, where multiple witnesses reported German losses, and where various evidence was gathered. Let's talk about the case of Norwegian pilot, whose Spitfire was damaged by debris from a Focke Wulf, which is IIRC not listed by GQ6. I challenge you to provide logical explanation to such cases, and not a simple note that there is nothing in the book.
Finally, about GQ6 reports, have you ever read Kafka? Or perhaps bothered to read newspapers to find some information about eurobureaucrats spending their time on classifying carrot as a fruit, analysing curvature of banana or inventing a standarised europenis? I bet they were quite busy trying to prove they are much more necessary behind their desks, rather than on the Eastern Front!

Don
Several points of disagreement.
First of all, Fighter Command claims varied through the period significantly, and no simple date of an end of overclaim can be established. Camera guns, were quite popular during 1941 and due to those experiences at the end of the year it was decided to introduce them as a standard equipment. Still, USAAF fighters continued rather high overclaim ratio well into 1944, despite their excellent gun cameras. I think it had more to general policy and verification system rather than to pilots themselves.
That said, German units continued to overclaim heavily, especially if combat was over sea. For example, it is believed (by Andy) that during the last flight of Bader, at least three Spitfires went down due to friendly fire. Therefore, we should subtract three kills from German victories, and add them to Fighter Command. Personally, I estimate friendly fire losses at about 10-20%, so this is quite substantial. It should not be forgotten, that several Fighter Command combat losses were due to accidents or malfunctions not related to enemy action. Thus, any statistic not based on individual research may be misleading.
Finally, how can you say that German data are excellent, if you wrote in your book that only two out of thirty KTBs have survived?