Timepiece (Stopwatch?), Japanese

Here is a highly unusual Japanese timepiece that is assumed to be military and WWII-era.  We speculate that it may have been either an aircraft navigator's timepiece or that of an artilleryman.

The main dial measures time, assuming to be in seconds (since it does not run), with one rotation from 0 to 100. The bottom left dial is labeled with the Japanese character for "Hundreds", and the right dial is labeled with the Japanese character for "Thousands". Each small dial has a hand that would rotate from 0 to 10 on that dial.  Assuming the measurement is in seconds, the timepiece could measure up to 10,000 seconds (or 2.77 hours) before completely turning over. 

The top knob is likely to have wound the timepiece, but it no longer engages the internal mechanism. It also depresses much like it would for a stopwatch. On the side is a metal piece that slides up and down, but whose purpose is unknown.

The back of the timepiece is hinged and can open without a tool. Engraved on the inside bottom of the panel is a very small Japanese character above the number 8 9 1 which is below a 3-petal floral emblem or logo with a Japanese character in it's center. The character below 8 9 1 is 京 and translates to the city of Kyoto, which may have been the manufacturer's location. We assume that these are identification marks of the timepiece and its manufacturer, but are unable to translate them.

The timepiece is contained in a thick brown leather case with a flap over its top. The case/flap has 4 loops that may have retained a strap. On the back of the case is a small pouch that holds a retaining clip.  How it might have been affixed to the case or to the timepiece is not obvious to us.  

The timepiece itself (out of the case) measures 2.5 inches high, 1.5 inches wide, and ~0.5 inches deep. The top knob adds ~.75 inches to its height. 

Knowledgeable visitors are invited to email us with any information that you may have on this curious timepiece.