Ryan Toews of J-Aircraft.com has been studying the markings of Zero aircraft for years. He worked with FHC staff to create all of the shapes, symbols and Japanese characters that appeared on Mitsubishi’s aircraft.
The one marking that puzzled staffers and volunteers was the small red “targets” on the wings and fuselage. The primary Mitsubishi factory in Nagoya had no adjacent airfield. All the Zeros produced by Mitsubishi were transported about 30 miles to facilities at Kagamigahara airfield. Each Zero was broken down into two ox cart loads for the three day journey. The major components were then re-assembled at Kagamigahara.
We suspect that these markings were applied to somehow better enable this re-assembly process at the airfield. Significantly, such markings are not found on Nakajima-built Zeros. If you know more about the transport and re-assembly of Zero aircraft at Kagamigahara, we’d love to hear about it. And, if you have photos of Zero aircraft where the marks are visible, we’d like to see those too.