You can adapt the Summicron Rigid v1 and V2 to Nikon S-Mount using an adapter. The Barrel unscrews from the Leica focus mount an can be mounted in an adapter made for use on a Bellows. Hack that into an S-Mount, done. On my list. I've seen this done long ago, bought the parts- on the to do list. With the choice I have in Nikon lenses, this is just a "You can do that, so I did". Kind of like you can lock up the mirror on a Nikon SLR, use an M39 to F-Mount adapter made for Bellows, Collapse the Leica lens into the SLR, and take a picture, It could be done, so I did.
Of course you can use the longer lenses such as the older Summicron 90/2, Elmar 90/4, Hektar 135/4.5 on a Bellows with a Nikon SLR. Nikon made a 39mm to F-Mount adapter for use with Bellows lenses.
I frequently use Nikon lenses on my Leica M cameras, film and digital.