I'm with the Artful Codger on this one. It's often a way of indicating in writing an unstressed, slightly higher sound. But the (liberating?) truth seems to be that "you" (and "ye") could be pronounced in a great variety of ways in northern English, Scots English, and thus a variety of forms made their way to Newfoundland. Both stressed and unstressed form will vary. And then there's the artist's own ideas, and his interest in comic effect, dialect imitation, etc. So go with what's comfortable.

I also was thinking a bit about "cat's meat". In 1920, the first Dr. Dolittle book came out (in England, admittedly), and Matthew, the cat's meat's man, is a prominent character in these novels. So I think I'd interpret "cat's meat" literally ('food for a cat') and place it in the same category with "turpentine", a rhyming joke. But maybe that was too obvious?