"it shot right up the charts and was played on our tv's Top Of The Pops for about 8 weeks running."
No mystery. It was rollicking good dance music for rock and rollers. therefore it appealed to the kids instead of the archivists. In other words, they breathed life into an old song which could have become a footnote in a history of traditional music. I say more power to them! I love to see someone like Nirvana performing In the Pines, Uncle Tupelo doing John Hardy, or the Grateful Dead doing Lonesome Road Blues. It blows the dust off of these tunes and brings new blood into what we call Folk or Traditional music. These songs are strong enough to stand up to these energetic bastardizations, and they will undergo these periodic resurfacings and modifications if they are good pieces of music, and whether the folks on this forum approve or not.