I haven't done any serious checking, but isn't it possible that BVD made long johns way back when the recording was new? They certainly were more in vogue then.

Another version to consider is that of Judith Durham, probably best known as a member of the Seekers, but who has done a good bit of recording on her own. Her version is from 1974 on the album The Hottest Band In Town,Volume 2. It is available on CD now.