If it weighs best part of a kg and needs a pair of stilsons to operate the ratchet, it could well be eastern european?

Niel

Probably made between the wars by a no name assembler supplying commodity instruments to tool distributors or direct to factory. Basically buyers would choose a standard frame, choose the micrometer head from a list and order a large quantity. Micrometer heads would have been bought in by the assembler. That one is unusual in having a proper adjustable nut and setting ratchet. The general run seem to have been rather cruder sans ratchet and having rather poorer markings. I have a metric 12 mm one that is pretty typical of the lower end of the breed.

Ordinary metric thread form cut direct in the body, fixed scale, screw adjuster on the reference anvil to set zero position and rather crude brass thimble fixed to the screw. Appears to be little used and surprisingly accurate. Good enough to use for real on anything that isn't precision job.

Yours won't be a proper, recognised micrometer make as that style of frame would be very old fashioned. Pretty much abandoned by the turn of the century when "proper" measurement tooling makers went over to more sophisticated forged bows and the like.

Clive

It looks like a shop made mic to me. I have a beautiful 0-1/2" in tenths Mitotoyo mic, satin chrome and carbide anvils, I bought it as a novelty, but it does come in handy in tight spaces.