Greybeard, thank you very much for your work!
But I have a lot of questions about Ki-44 subtypes and about your pack installing ...
I beg your pardon and thanks in advance.
In pdf-file indicated, that you took info about armament, gunsights and production number of Ki-44 subtypes from Wikipedia.
The same info is in
Osprey Aircraft of the Aces 100 - Ki-44 ‘Tojo’ Aces of World War 2 by Nicholas Millman:
But in
Osprey Aircam Aviation series 025 - Nakajima Ki.44 Shoki Ia,b,c/IIa,b,c in Japanese Army AIr Force Service by Richard M. Bueschel (you recommended me this autor in ''Nakajima Ki-43-II Early production model'' top) I found this info:
What subtypes are Ko, Otsu and Hei in this book?
Is there Ki-44-IIa = Ki-44-IIKo (seems strange that only 3 built), Ki-44-IIb = Ki-44-IIOtsu (seems strange no cannon armament) and Ki-44-IIc = Ki-44-IIHei (seems strange the presence cannon armament - 20 and 40 mm) ?
Same info about cannon armament of Hei (not Otsu) subtipes I found in
Aircraft Profile 255 - Nakajima Ki-44 Shoki ('Tojo') by John F. BrindleyWhat are you think about this armament info and about Ki-44-IIKo production number?