L
Interesting conjecture, but I'd say no because:
1. My grandfather served in France in World War I, and trained troops in World War II, so he had no exposure to the Pacific theatre.
2. Unless kendo swords (which I think are two-handed) have a knuckle guard that extends all the way back to the pommel, these aren't.
3. My father specifically referred to them as "mock swords" (after websearching, I understand why you might think what you did). I don't recall whether they were meant to spare the dress sword the wear and tear of daily drill, or if they were made because of metal shortages in the early years of World War II.
They had "U.S." stamped on the knuckle guard.