Odd Copal Shutter

I went to a camera show this morning, picked up a couple of odds and ends including a somewhat odd Copal shutter.

Size 0, cock and shoot, with cable release socket. No diaphragm, no flash sync. Speeds marked T, B, 1, 2, 5, 10, 25, 50, 100, 200. Face place marked COPAL-II at 12 o'clock, CPL at 3 o'clock, and COPAL again at around 7 o'clock. There's a retaining ring, also a locating pin sticking out of the back.

The front is threaded internally for #0, has a screw-in insert that holds a thin piece of clear glass. The rear is not threaded internally.

It has to be fairly early; google found a reference to an Olympus Six folder made between 1949-53 with a Copal shutter that had the same speed sequence.

Any ideas about its intended use?

Thanks,

Probably this shutter is for use on a microscope adapter. these are usually prontors, but I guess Copals could have been used as well.