A point I should make, to respect the point of the thread, is that my initial idea was actually to go to a multi gear 2 or 3-by setup. But based on the points just discussed, it is too hard to do that on this project. Besides I have a grail Mercian
King of the Mountain build coming up soon. It has an already aligned and cold-sett status,very light thinner531 db, and with geometry similar to the Rudge (and to a Trek 720). The Rudge, while fully 531, is only claimed to be fully straight-gauge.