What's this odd antique?

[Snubs]

Now the eagle eyed may realise that this isn't a watch, it's a clock. But what i'd like to know is what is it for? It clearly has a purpose, but i've yet to find out what it is. Here are some pictures:

The front, in its case:



Front out of its case:



Rear out of case:



The inside:



It's the inside that i find particularly interesting as there is a roll of ticker tape at the bottom. There is no way for the ticker tape to come out of the case, other than by unlocking the back with a key. The case is on a shoulder strap. Size wise, i'd say it's about 30cm in diameter and maybe 15cm deep. Weight wise, it's very heavy!

I've heard a few theories as to what it might be, but if anyone could provide something definitive, or where i might go to find out, it would be much appreciated. It was found in the home of a relative who passed away recently, so that's a bit of a dead end (possibly not the best turn of phrase).

Thanks

[Snubs]

Thanks, i think you're probably right. A bit of googling around that brought up quite a few pictures of very similar items.