The original Angel Air bottles were HSE & DOT tested, there was some confusion over this originally because of the diffferent testing criteria for both standards.
However once the bottle has been retested it will then be only able to be tested and used in the appropriate region. As Crumpler has already stated these bottles only have a 3 year life before retest on them, and I would have thought that this has already been reached. So if it has been retested it no longer is a dual standard bottle and can only be used in the appropriate region.