I agree that the Nikon's image circle wouldn't be big enough to cover. I think you need something from a larger camera. Maybe a 65mm Angulon from a Linhof 23 would work, then see if you can adapt it. As with converting a 120Pan Holga you would mount the lens onto an M42 metal body cap, then mount that on a M42-M42 12-17mm focusing helicoid, then mount that onto something like an M42 to Nikon (because of the small bayonet flange) adapter that is screwed onto the modified Holga body.