I recall the last verse as sung by Alex Campbell [but I stress this is from memory] as

Willie never smiled again that anybody saw
But he said "I have to part".
The last heard of him he was in Montreal
Where he died of a broken heart.

I sing it thus on my YouTube channel.

The 'never smiled again' motif is familiar in English tradition from a story of King Henry I, who mourned the death by drowning of his much-loved son ~~ "King Henry had only one other legitimate child, his heir, Prince William, a boisterous young man whom the monarch completely idolized. Tragically, in 1120, the prince was needlessly drowned - along with many of his generation at court - while making a return trip from Normandy in the 'White Ship' which ran aground and sank. It is said that Henry never smiled again." [David Nash Ford's Royal Berkshire History]

I learned that at school in the early-1940s.

~Michael~