Now that you folks mention it, I remember the second half of the song (I admit I had completely forgotten there was more to it). The version I remember was ever so *slightly* different from those posted above:

Let all men come together.
Let all men work together,
Striving to make the world better,
Pledging our lives for peace.

Also never realized it was a round (although once you mention it, it seems obvious) -- which is lovely to know.

Tinker... this is a long shot, but I don't suppose you attended Narrin GS Camp as a kid (in the 60s; Southeast Michigan)? Thing is I remember a girl whose nickname was Tinker; we both particularly enjoyed singing. Even got together once after camp ended. If you want to contact me off-list, my @ddress is vikki@srama.demon.co.uk

Cheers.