Why not just use the pc ports ?
The OP is looking to take advantage of the TTL flash metering capability of his camera. Actually, the PC port on the lens must be used as well, and the Hasselblad SCA adaptor has two leads, one for the meter in the camera body, and another that connects to the shutter's PC connection.
AgX beat me to it for recommending SK Grimes for the mechanical adaptor. It might be possible to adapt a Hasselblad bellows lens hood adaptor ring to the flash, without resorting to a lot of custom machining. The adaptor rings are fairly common in the used market sources.
With google, I found a document that details the Nikon TTL interface
link. There is likely something similar floating around for the Hasselblad signals, but bridging them probably requires some custom electronics. I would guess that the SCA adapters would likely not be terribly useful for bridging the two, but it might be possible.
Calculating exposures using the flash's computer, or else a separate flash meter seems like a much easier process unless you're planning to do quite a lot of macro work.