quart is (at least where I live) pronounced to rhyme with wort (or, I dunno, sort).

I think it's a regional/accent thing. I'm on the West Coast, and I've always used (and heard) the DS9-style intonation of the word (which, to my ear, sounds a lot more like "quart" than "lark").

Midwesterners and New Englanders are probably more likely to hear and use the "lark" pronunciation in the word. (And the James Joyce explanation needs to take into account that Joyce, being Irish, would have pronounced and rhymed things a bit differently from an American).