Before the war, numerous Japanese engines, vehicles and components were license built from Western designs. Mazda produced GM truck designs, Sumitomo produced Hamilton Standard propellors....and so on.

I was once told that early Toyota and Nissan 4-bangers in the late 60's and early 70's were US designs that were never introduced Stateside during the economy fad that almost occurred in the early sixties. The Japanese manufacturers improved and "perfected" some designs and you know the rest. On the other hand, the German DB-601 license built inline engine was plagued with troubles.

Since new radial engines introduced by Japan during the war were somewhat unreliable, and parts for the "good" ones would be impossible for the Allies to obtain, I'll bet the P&W plate is on a P&W installed for this reason.