Bordkanone, sorry for what I'm going to say. Those Japane aircrafts are really well done but they are smaller thant they should be. It was especially the Ki-100 that got me that feeling of being underscaled, so I took the libery and went checking.
The Ki-21 bomber is 16m long so in FD scale it translates to 353pixels (16 x 22.093), yours is 336 (353 with the machine guns but I do not think they would count in the plane length figure)
the Ki-83 is 12,5m long so in FD it translates to 276 pixels, yours is 238.
the Ki-100 is either 8,92m (according to Watanabe) or 8,82m (according to Gakken), which is either 197 or 195 pixels. Yours is 183.
Sorrry again, no ill intent whatsoever from my part but I feel you needed to know.