Aquatica built a custom housing for Amos Nachoum and his Xpan, so if you're not set on a vintage Hasselblad made housing, you could see how willing Aquatica would be to doing a one-off.
You could also post on a Hasselblad specific discussion board, as those users might know where to find a housing even if they're not u/w photogs.
You could also post on a Hasselblad specific discussion board, as those users might know where to find a housing even if they're not u/w photogs.