Lyric1 has just found some more info on this aircraft and it seems I have misinterpreted the scheme. So I have adapted the skin to match this new info.
The leading edges of the wings were not natural metal as I had assumed but painted, most likely in red. This was due to a High Command August 1942 directive to paint the inner half of the wing leading edges of all aircraft either red or yellow for IFF purposes. Initially some units mistakenly painted the whole leading edge which seems to be what's happened here. While yellow was almost universally used for this ID marking later on here the shade seems to match the red of the Hinomaru marking so that's what I have gone for. The leading edge of the fin may have been painted as a visual aid for the dorsal gunner to prevent him shooting it off.