... Any advice before I do any thing silly ...
Yeah. Don't do anything silly.
There must be loads of watchmaking enthusiasts' Websites around, why not post your photos on one or two of them?
There's a place down the road from me that has cabinets full of things which to my untrained eye look a lot like that. They seem to sell for anything from thirty quid to a couple of hundred. But I bet there are some that wouldn't look a lot different to me that are worth thousands.
I wouldn't recommend that you take any one recommendation. If you see what I mean.
Is is a family thing, or did you pick it up in a charity shop or something?
The fact that it has two winders and a lever (switch) makes me think it might have an alarm.