Can I just say that we made it quite clear in our article that Walter used the melodion as a guide for himself to judge the age of tunes - whether it was accurate or not is immaterial - it worked for him and in our experience, his judgement of tune ages was pretty fair
We recorded him elsewhere on this subject and he said that the only tune he can remember ever being thrown on was 'Black-Eyed Susan' (he discussed this with Mike Yates who wrote an article on his tunes, I think)
I'm no musician, so I can't say whether his method was right or wrong, and to be frank, if I could, I wouldn't try to prove him wrong - if it worked for him, it worked for him - end of story
Walter wasn't a good musician - he never claimed to be and I never saw him play his melodeon or his fiddle in public
Jim