I would not like to say for certain where it is from, but I would not rule out Belgium as a probable source. I understand why one might think about Scotland as the origin: I once had a very similar weight (same green ground and style of base) with a cap badge inside, which I thought might be Scottish (if I can find any images of it in my archives I will post them). However, it did not look quite right, and when I got the item below I concluded that it was (like quite a few cap badge weights) from Belgium.
The base treatment of the religious sulphide is different to the one you show, in that it has been rather crudely ground concave and polished. The grouping is quite common in Belgian weights - I have seen it in some well made Val St Lambert with torsades, too.