A friend of mine recorded some of his favourite ballads and songs and gave the tape to me. That was ages ago and, unfortunately, I haven't been able to keep in touch with him, so I can't ask him which LP he took the song from, but he included another song, a version of My Johnnie was a Shoemaker. Does it give you any clue? Most probably both songs come from the same source. The refrain of Charles... goes like:

Trusty Cambpell, stout Glengarry, gallant Gordon wise Locheill, bid the clansmen altogether, fast and fell and firm as steel. Or so I get. Thanks.