I don't know where to start to try and find out so thought I'd post on here due to there being alot of knowledgeable people on here. I saved it from being thrown out when I was clearing a Quantity Surveyors office out.

I looks a neat little thing so thought it might be worth something. No one seemed to know what it was in the office.

 

I'd say it's the remains of a tape measure

 

Forgot to say it has an adjustable lense inside which makes me think the unit is complete.

 

what i was going to say marc, the old wind it up yourself jobbie