Does the Hassie have an FX crop mode?
The image circle of Nikkors is a good bit smaller than medium format film, so you'll be wasting a lot of image space even if you can get them to fit.
Edit: thinking a bit more about it, I'd guess that the mount-to-sensor distance is a bit more with the H1 than with Nikons, so your Nikkors won't focus out to infinity. A bit like having the lens on an extension tube all the time. Also, there's the small matter of the leaf shutter in the lens...
Chris