You might be interested in the form of the song as sung today among Dartmoor singers;
Tom Pearse,Tom Pearse,lend me thy grey mare.
Right fol,fol de rol.diddle I do.
For I want to go to Widecombe Fair.
With Bill Brewer,Jan Stewer,Hugh Davey,Philly Winkpott,George Parsley,Dicky Wilson.
Tom Cobbley and all.
Here,here's Uncle Tom Cobbley and all.

Bill Murray,the great Dartmoor singer, sings it like this and the chorus has a slightly different tune.This version is considered definitive down this way.