[ArtieBob]

IIRC, the U.S.Navy quad 40 mounts still had ring and bead sights (for manual pointing and training). However, the Mk 56 fire control system that I remember had gyro lead computing , but was remote from the mount, electrically linked. The cable bringing in the signal to the mount could take a total of 720 degrees twist (360 each way, before having to be manually untwisted). The electodyne drives were very fast in slew and first loaders needed to be well braced as we could get flung off the mount if we were not careful. I have no idea if the Mk 56 was in service during WWII, but the ship I was on in during the 1950s appeared to be pretty much in WWII trim except for the 20mm mounts having been torched off. You are absolutely correct that there was not much reason to upgrade the 40mm after WW II. The 3"/50 mount I mentioned was not the manually loaded WW II version, but the semi-automatic twin mount that was designed to be a drop-on replacement for the quad 40s. This was a direct reslult of the kamikaze attacks and the need not just to "kill" the attacker, but literally have enogh blast and kinetic effect to knock them out of the sky. I believe they were barely too late for WWII.
Next comment, I remember watching the bursts around the towed sleeves, since I was second loader on the 5"/38, I would not have been able to see what was going on during AA practice (gun house). And since I was seeing bursts, if they were 40mm, it would seem that they would be from VT, since I do not remember the 40mm having a mechanism for setting fuzes. But, as I said, my memory could be getting fuzzy after more than 50 years.
Final comment, VT fuzes were apparently restricted to naval use for most of the war, primarily so there was little possibility that unexploded fuzes could be recovered and copied by the enemy (a la H2S).

Best Regards,

Artie Bob