Hi Trev,
I first thought it was an British engraving because of the garter collar. It has since been pointed out to me, by someone with much keener eyes, that above the jewel is a winged harp which means this is a collar for the order of St Patrick.
http://en.wikipedia.org/wiki/Order_of_St_PatrickSo, combined with the Earl's coronet, there are only two possibilities: Henry Loftus (1783) Earl of Eley and Charles Loftus (1794), his nephew.
Since Henry Loftus died in Bath two months after he was appointed but before he was invested, I think it's more likely that the box belonged to Charles Loftus before he became Marquess of Eley in 1800.
I can find no evidence that either was ever in Sweden, so most likely it was given by a foreign visitor.
Miles