It looks like it mounts to the shutter speed dial. Does anyone know if it's an Olympus accessory and what it was called? I still don't understand how it works; it looks like it couples to the shutter speed dial somehow.
1967 where are you?
There's a two eared mount around the SS dial, it just clicks in place.
You can see the lens for the CDS cell on the front of the meter, the smaller round thingy o top in the picture
It read from the top like the real old Pentax clip on meter.