Came across this ongoing debate by accident.Just to confirm that I wrote the additional verses

And will ye go tae Flanders my Mally-o
Tae see the bonnie sodjers there my Mally-o
They'll gie us pipes tae blaw
Coats o red an kilts sae braw
The finest o them a' my Mally-o

And will ye go wi me tae Flanders my Mally-o
Gin I'd take the royal shillin my Mally-o
Wid ye tae a foreign shore
A' tae hear the canons roar
and the bloody shouts o' war My Mally-o

I sang the song with Ossian but never recorded it. When I left the band in 1980 Tony (Cuffe) carried on singing the song and recorded it on the Dove Across the Water album

Tony and I sang it together for a final time at the Ossian reunion at Celtic Connections in 1997. As other contributers have said the song dates from 1706/7 and appears in a number of early collections