Thanks again Matti
So there is a WNr 6431 as well. Both 6430 and 6431 are so close to 6429 that they both feel very much OK.
I will list both of them as definite while 6490 will remain "bogus".
With regard to WNr reports, indeed, I was making a mental comparison between GQM and NVM and of course understands the general situation you express.
Best thing, no doubt, is to have manufacturer's reports/lists, but when it comes to Luftwaffe there will most likely always exist so many gaps that some form of educated guesswork is needed.
Discussions on TOCH is therefore very beneficial, at least to me
Cheers
Stig