[GerritJ9]

This would be a reverse of what Kawasaki actually did; add radiator from Ki.61 to Ki.100, cut off the Mitsubishi radial and replace with the Ki.61's nose. The Ki.61's pit would probably also be required- seems more accurate for a liquid-cooled bird. This would take care of the visuals though possibly a few minor details would have to be added/changed as well. Result the razorback version, the bubble top would obviously require more surgery.
Best person to supply the required info on the Ki.61s is undoubtedly Billfish.