Hi BB, if you are about to have a pair of single deck and a pair of twin rail side plates, all dressed up so they can be laid one over the other for a very accurate comparison, that will be a substantial step forward for this project. Deejay has told me he is fairly sure his twin rail has the drilled holes in its side plates that were originally used to mount the single deck, and were re-used by the factory as weld holes for the twin rails. If we can verify that by actually laying one over the other, it will greatly simplify the future conversion process. It would mean the original holes just needed to be drilled out, to convert side plates. (Of course this would need to be done very accurately, since those holes establish the accurate alignment of the frame.)

Once we fully understand the side plates and have a plan for how to convert them, the only other issue seems to be capturing the detailed design of the deck.