I have not laced up this combination before. I would think you could lace it and then mount it in the frame with the axle. You could then adjust the offset equally to the frame side to side, keeping in mind tire clearance to the chain. Don't know if that helps you or not.
I'm jotting a lot of this project down...looking at pictures...then back at my concept and trying to answer technical problems that come up in my mind. The frame I'm looking at has open axle plates. I can't seem to find any thread or book, or set of pictures which shows me how to tackle that particular mounting issue. It's greatly different than my friends bike, and nothing like the stock '69 A50 I have.