Rate of Climb / Vertical Speed Indicator, Model 1, 100 M/M, Japanese Naval Aviation

This is a fine specimen of a Vertical Speed / Rate of Climb Indicator, Model 1, as used in aircraft of the Japanese Navy during WWII.  It measures rate of climb or descent in up to 100 meters/minute.  The calibration screw is on the rear of the instrument at the 3 o'clock position. Although the instrument is missing its data plate, it appears identical to the one illustrated in Robert Mikesh's book Japanese Aircraft Equipment 1940-1945, see photo, which was made by Tokyo Koku Keiki.

It is in good condition given its age. The glass is intact.  There is some paint chipped on a few edges. Measures ~3.25 inches across and ~ 3.5 inches deep.