No problem with deviating from the words Marcus - I do it all the time.
The idea of unnecessarily lengthening a song with 23 verses would daunt most audiences.
I found when I did perform if that the rhythm of the song fits in perfectly with the picture of two men moving down a field swinging scythes it helps the movement of the narrative.
I had occasion to learn to use a scythe when we moved into this house 15 years ago and was forced to tackle the acre of field we laughingly refer to as a garden - song and physical motion - horse and carriage, as they say.
I can't see how a chorus can be anything but an encumbrance.
MacColl was the one who introduced it to the revival as far as I',m concerned, never heard anybody else perform it.   
Glad you came back Marcus; I was intending to re-open this thread and ask you about a song Ewan sang which he and Joan recorded during the making of the Ballad Hunters
It's called 'T'owld Chap Cam o'er the Bank' an extremely bawdy version of Seven Night's Drunk.
I learned it years ago, but have always had to be circumspect in choosing when I sang it - I haven't sung it since we moved here; not sure that Catholic Ireland is ready for it!
Have you come across it at all?
Jim Carroll

TH' OWD CHAP CAME OWER THE BANK.   
From the singing of Harold Sladen, Openshaw, Manchester, Easter 1934.

Th' owd chap came ower the bank bawling for his tea
Saw a pair of mucky clogs where his owd clogs should be
Come Here wife, come here wife, what's this here I see,
How come this pair of mucky clogs where my owd clogs should be ?
Oh you owd bugger, you daft bugger, it's plain as plain can be
They're just a couple of pickle jars me owd mam sent to me
Oh I've been ower hills and dales me lass, and many a grassy moor,
But girt hob-nails on pickle jars I've never seen before.

Th' owd chap came ower the bank bawling for his tea
Saw a coat on back o' t' door where his owd coat should be,
Come here wife, come here wife, what's this here I see
How come this coat on t' back o' t' door where my owd coat should be ?
0 you owd bugger, you daft bugger, it's plain as plain can be,
It's just an owd pudding cloth me owd mam sent to me.
Oh I've been ower hills and dales me lass and many a grassy moor.
But buttons on a pudding cloth I've never seen before.

Th' owd chap came ower the bank bawling for his tea
Saw a head on t' pillow where his owd head should be
Come here wife, come here wife, what's this here I see
How come this head on t' pillow where my owd head should be ?
Oh you owd bugger, you daft bugger, it's plain as plain can be
That's just a girt big turnip me owd mam sent to me,
I've been ower hills and dales me lass and many a grassy moor
But a girt big turnip full of teeth I've never seen before.

T' owd chap come ower the bank bawling for his tea
Saw a pair of hairy cods where his owd cods should be
Come here wife, come here wife, what's this here I see
How come this pair of hairy cods where my owd cods should be
Oh you owd bugger, you daft bugger, it's plain as plain can be,
They're just a couple of garden spuds me owd mam sent to me
Oh I've been ower hills and dales me lass and many a grassy moor
But garden spuds with airs on I never saw before.

T' owd chap come ower the bank bawling for his tea
Saw a great big standing prick where his owd prick should be
Come here wife, come here wife, what's this here I see
How come this girt big standing prick where my owd prick should be
Oh you owd bugger, you daft bugger it's plain as plain can be
It's just a home grown carrot me owd mam sent to me
Oh I've been ower hills and dales me lass and manv a grassy moor
But a carrot diggin' a girt big hoyle I never seen before