Italy's co-belligerent navy in an extended Pacific war

Did Italian forces fight for the Allies after 1943, and might the Italian Navy have joined a prolonged war against Japan?

Italian troops and ships already served alongside the Allies after the 1943 armistice, and their naval forces would likely have been drawn east if an invasion of Japan demanded every available ship.

Italian ships and troops did fight on the Allied side after Italy changed sides in 1943. Their contribution is therefore not purely hypothetical. If atomic weapons were unavailable and the war against Japan required a vast new deployment, Italian naval forces would likely have been among those called forward. Their role broadens the usual Anglo-American picture of the late-war Allied coalition.