Hi Ludo,
Yes, modelling sites & profiles are valid sources, but wherever possible I try to find a photo to back up any profiles I see. So often these photos are black & white, & I often disagree with some elements of interpretation of colouring put into a profile.
Doing further research & trawling through books or more academic reasearch sites & forums can often yield a much better understanding of the circumstances any photo was taken - so often the captions are wrong or mistakenly identified - more frequent than you think!
It's a while since I did the 205ku skins. IIRC I was looking for info as part of the BPF Iceberg research & transcribed the unit history from a reference book in a Library. The aircraft markings were largely derived from the info gleaned from j-aircraft.com about "standard IJNAF markings for the early '45 period...
Here's a quick list of websites I use for research, with some comments of how I use them...
j-aircraft.com - don't forget the forum, sometimes good photos & discussion points are hidden away in the archives
pacificwrecks.com - often used for airbase/scenery details, but also a great index of aircraft types, clicking on these gets you a listing of individual aircraft & sometimes these describe appearance, or have photos to support
combinedfleet.com - mainly for shipping, but the TROMs can provide details for anti-shipping strike set-ups
propnturret.com/tully/ - the forums associated with combinedfleet.com. Again, naval bias, but a great source of details of ship operations.
http://www.aviationofjapan.com/ - modelling bias, but a great source of knowledge for JAP aircraft appearance etc. Some interesting video links, & some unit/operation details hidden in the various narratives.
https://arawasi-wildeagles.blogspot.com/ - like aviatonofjapan.com, but more historical research/discussion
https://ww2aircraft.net/forum/ - often a google search for a particular unit/pilot/aircraft type will lead you to a discussion on this forum. Surprising level of detail can be found if you take the time to scroll through the various discussions.
https://www.britmodeller.com/forums/index.php - modelling site, with a UK focus, but some useful detail/discussion/research info hidden in the various discussions here. I find the site search is poor, so I often google search & put "britmodeller" at the end of my search terms, it generates a much better set of results.
https://forum.rafcommands.com/ - like ww2aircraft.net, but focussed on UK airforce. Sometimes has nuggets of historical detail in amongst the discussion threads. Like j-aircraft.com forum & propnturret/tully/, just searching through the discussion boards & archives can reveal a surprising amount of details on a variety of subjects.
https://www.royalnavyresearcharchive.org.uk/ - a collection of RN websites, detailing airbases, carriers, & naval squadron histories. Sometimes good photos & serial numbers/pilot names in amongst the histories. The airbases website is worldwide, & often includes layout drawings.
I hope these notes help you out some.