Relayed question about silver stamping

I’m hoping that someone can shed a bit more light on this

I recently received this email:

I recieved a gift many years back from the mother of a good friend.
It was a silver bracelet and was old. The only stamp/ identifying
mark on it is a "1000", which I assumed related to the silver
content. It is old. It's design is middle Eastern and very
intricate and clearly handmade. Do you have any idea when they last
marked silver in this way, or any other idea Re: it's age? Just
curious (the "Antiques Roadshow" hasn't been by lately). 

This was my reply:

The “1000” mark is interesting…

If something is stamped “925” that means that it’s sterling
silver (92.5% silver) and if it’s marked “999” then it’s fine
silver "99.9% silver). I can only assume that a “1000” mark
means 100% silver, but I’ve never seen that mark used.

If you have any more to offer, I’m sure this fellow
would appreciate it. His email is bob.mengay AT sympatico DOT ca

-Spider (interested to see what people come up with)