Hey Hrothgar and Old Git !
As the Jordan in the above recording of the Manchester Rambler (Re Visited) I will support the re write of a classic song. I think that Mr Tams observations on land ownership are thought provoking, to say the least.
And Yes, the old version isn't "Broke"...You can't break songs, only, lose them by NOT singing them, as Mr Carthy once famously said.
(And, I haven't heard the original Rambler for many a long year, maybe it might get aired a bit more frequently now.)

If all songs are sacrosanct, (As you seem to be suggesting) Then that's the whole of the Kipper Family ouvre out the window for starters!!

Not to mention every regional variant of other songs, and while we're about it, all musical instruments, classical arrangements etc, etc....

Blimey, I'm straying into "What is Folk song" territory...Nurse, the screens !