Thanks Matt, the Manxman mufflers are quite different from the other Norton mufflers (silencers) , as far as I know, the only Norton built mufflers (due to a deadline to export to the USA).
I have recently purchased a copy of the Cycle World article from March of '62 you have shown, interestingly, that is the 2nd or 3rd issue of Cycleworld as the had just begun publishing in 1962.
I have a few leads where I may be able to borrow some of the exhust parts in order to have something made, but I am not against restoring an old set & re chroming.
I seem to me a magnet for the unobtainable parts
model 77, Nomad, etc.
Thanks again to everybodys info !