Silver (which are stainless BTW) are Tenneco, at least with part number 11B1538CP_02. Those are supposed to be for a 720sLatest Info - the black ones are actually from Integral (www.fst.com). They don't make them any longer and won't make them again.
I'm assuming the silver ones are Hydac - can anyone confirm?
Those are the big two companies. I've sent the details and pictures I have to a smaller company and await feedback.