Super thin, 19 jewels, 8 adjustments marked IOCO
Watch Co. Sorry about the scans, camera is not that good for macro.

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I have a dozen V&C pocket watches, none with a movement remotely similar to yours. I don't recall ever seeing a V&C movement like yours.
However, I have a C.H. Meylan that looks almost identical to your movement, except for minor differences on the pillar plate. I also have three seemingly identical Cressarrows that I have always thought to be C.H. Meylan PLs.

C.H. Meylan watches are notoriously variable. I hardly every see any two that are completely identical. Hence, the minor pillar plate differences do not suggest to me that your movement isn't a C.H. Meylan.

"Ioco," according to Pritchard, was an Ollendorf brand. Pritchard says that Ollendorg was an exporter, not a manufacturer.

Pillar plate