I took these pix of a pair of Japanese medium Caliber AA guns.
They were recovered from Eastern New Guinie (one is definetly from Wewak area) and are on exhibit at the Imperial Japanese War Museum, Yasakuni, Tokyo.
Also the US 90mm was no slouch. I remember watching a show on discovery channel a few years back, on how back in 1945, it was slaved to a radar and an experimental ballistics computer and could actually automatically track and hit on the first couple of salvo's low and middle flying aircraft.