Brass Plate

[gothicromance]

I have a brass plate that appears to be hand hammered.  It has a star of david in the middle and lots of other ornate markings in it.  There is a hammer mark on the back along with some middle-eastern looking characters in an oval surrounded by what appears to be a rope.  Does anyone have any ideas as to where to find out more information, including but not limited to it's value, origin, maker, age?

Let me know if a picture would help...

Thanks.

Joan