On p. 599 "H. H." attests to having heard the song "as a boy."

Naturally, he doesn't bother to tell us when or where. He gives the pattern ("sung as a monotone")as,

What shall we sing O?
We will [sic] sing the ones O
One is one, etc.

Then:

What shall we sing O?
We will sing the twos O

...and so on to twelve, "always repeating the numbers all back to one." The list posted by Q represents the final "stanza."

Also on p. 599, J. H. Payne of Kildare Gardens reports a quite similar song as having been sung by "the children at Beckington, Somerset, in 1867. Payne's finale:

Twelve is the ring of bells,
Eleven is the gate of heaven,
Ten is Our Lady's hen,
Nine is the water wine,
Eight is the crooked straight,
Seven is the bread of leaven,
Six is the crucifix,
Five is the man alive,
Four is the open door,
Three is the Trinity,
Two is the Jewry,
One they do call the Righteous Man,
Save poor souls
To rest, Amen.

Payne cannot explain "Ten is Our Lady's hen." He wonders aloud if it could have anything to do with the saying, "As nice as a nun's hen."

Which is a new one on me. Unlike in the better-known song, the numbers here are given rhymes.