I have two items to add here. One, it would appear that there are, or were two groups called Coven. I have the lp by Coven called Witchcraft put out by Mercury stereo SR 61239. It is stated inside as being the first Black Mass to be recorded. The album is from 1969. Obviously, One Tin Soldier is not the starring single on this album. So, my best guess is that there were two groups. My second point is that a young lady name of Skeeter Davis (yes, the one that sang "The End of the World") came out with an album called Bring it on Home in 1972 which begins with "One Tin Soldier" It came out on RCA LSP-4642. So, I wonder if there were any other singers who filled their albums up with this song around this time.