That "Kurstee" pronunciation is due to the tendency to make an "uh" sound of short "i" - so "milk" becomes "mulk" and so on..

I'd have said that's a West Coast/Central Belt tendency though. My mother used to go mad if we said "mulk", and used to insist we said "th-ih-rty" and not "thur'y"

The linguistics of accents are interesting.

A lecturer (in linguistics) told me that "pearl" as pronounced by a Scot from Edinburgh was almost indistinguishable from "petal" as pronounced by US speaker ( I forgot where specifically he said in US, and can't be bothered making it up).

Cheers (pronounced "tsheerz")

Steven

pronounced "steee-vn"