Norseman

Hi there!

I am new in here. I have got this medals/orders from my grandmother 30 years ago, and she got it from an great-uncle who was working as a diplomate(?) in Persia in the 1880ies, I think, but I am not sure. It is a set with a breast star, 87 mm in diameter, and a shoulder sash with a smaller star, 74 mm in diameter. It is made by Kretly in Paris. It comes in a black leather box from Kretly that is a little worn. The shoulder band is also a little worn, as I have let my children play with it... But the stars are in pretty good shape, and luckily there are no damages to the enamel as far as I can see.  I really don`t know much about it, but this seems to be the right place to ask.
Could anybody tell me a little more about it? How old is it? Is it silver? Should I polish it? Is it worth anything?