I recently purchased this very interesting bottle for $150. The bottle reads Milnes & Son Bradford Undercliffe and on the other side has a picture of a boy on a donkey with trade written above and mark written below the picture. The bottle has a base color of a greenish aqua and is marbled with brick red and white. After a very close examination, I'm convinced that the coloration is beneath the surface of the glass. Any insight into the coloration and value/rarity would be greatly appreciated.