Strange camouflage on Ki-43-III

[Skyraider3D]

I recently made an interesting discovery. These well-known photos appear to be showing Capt. Miyabe's Hayabusa of the 2nd Chutai, 64th Sentai. It is often captioned as a Ki-43-II. Some profiles caption it as "Ki-43-II-Otsu, Burma, spring 1944". This however must be incorrect, as there are several points that identify it as a Ki-43-III:

- methanol filler cap in the sliding canopy
- methanol filler tube behind the headrest
- fuel cooler under the wing
- short gun blast tubes

If this is indeed a model III, then it has most interesting camouflage as I believe all production Ki-43-IIIs were finished in late war brown!

Could this be a pre-production model III, being on trial with the 64th Sentai, and thus the reason for the photo shoot?