Ikelite was the name of the maker I wanted to remember.
They were the best known housing maker I ever heard of and they made both Hasselblad and Canon, etc for 35mm brands.
If I recall correctly, a Hasselblad case ran $5000 - $7500 US back in the late 1970s into the 1980s and I believe they were guaranteed to perform to specs.
That last bit may be wrong, but I do no think so, no in dollars in that era.
I have a Canon for my $(&#&@/ G10, but build quality does no compare to the heavy, film camera cases they built for professionals.
I also had a Nikonos IV with a 35mm which I liked for skin diving but I sold it with an eye for a manual capable Nikonos V some time in the future.
If you go that route, get the 35mm and 85mm which are good above the water as well
Godspeed to all.