Thanks JacobS, that is very helpful. What needs to happen next is that I win the lotto, take this violin and the real William Luff I've seen (bought in person by the current owner from him), go and visit you, and remunerate you appropriately for an intensive tutorial on this matter. I may not thereby become an "Englishman", but I certainly will gain some insight. Seriously.
My sincere thanks to you and other contributors to this thread. All in all, an informative climax to a not-too-bad day. Tomorrow morning it's the Springboks against All Blacks, while I'm holed up in the workshop with work, appointments, and training of an apprentice. But there will be multiple repeats of the game over the weekend.
Again, thanks to all for responding.