I acquired my Hugh Banner hook from Tom Furey in 2012.
This hook is 131 mm. tall, 79 mm. wide, 11 mm. thick, and weighs 89 g. It was made by bending an 11 mm. aluminum alloy rod.
There are no markings on this hook.
Tom was able to obtain a number of items from the HB factory closing, and there were several hooks like this in the set. I am not convinced that this hook was intended to be a descender - it looks like it is a hook for hanging harnesses. I asked Tom about these, and he replied, "I don't have a definite answer. They were in the HB factory when I cleaned it out and they were with all the other figure of eight devices in a box. I have used one as a descender and it worked quite well, but they could just be hooks." I debated including it, but since Tom tried it as a descender and it worked, I decided to share it here. The opening in the eye will let this hook come off your seat Maillon, so for safety's sake, I do NOT recommend it as a descender.