Just found it on a Wiggy Smith song album, sorry.
'I went to put the horse to the grass'


By the way in the version of Old Horse that Jim Eldon collected and Crucible sing so well ( credit to Simon Heywood)I've heard old cherry old grey in the chorus as well as old chavi old grai.

I wonder whether old chavi could mean old lad or old boy.

Chav seems to have become a term of abuse !

Cheb in Arabic means youth I think. Round here in Sheffield a chabby or chebby commonly means a baby amongst local folk , not necessarily gypsies.