Speaking like a Maine-ah

I just came back from a trip to Maine, where I snapped a picture of the following sign in a diner window in Camden:

This got me to wondering what the phonological and phonetic characteristics that embody the Maine accent are.

A very cursory search of the web and a couple books suggests that the Maine accent, like that of John McCarthyÂ’s Massachusetts, is non-rhotic and contains epenthetic /r/s. According to Wikipedia, we also learn that:

Many Mainers (locally pronounced maine-ahs) use the phrase “right ruthless” (pronounced right roofless). This usually means that something is in good form, e.g. “I’ll tell you, it was right ruthless when you flipped your snowmobile back there”.

(If this is true, then it makes me wonder if the substitution of /f/ for /θ/ is a general property of the dialect, or localized to this particular expression. )

Small (1999) also notes that instead of the low vowel /ɑ/ (small letter alpha), many Mainers use /ɒ/ (small letter turned alpha) instead. This also seems to affect /æ/. But again, this may be common to other parts of northern New England as well. So, while this is admittedly a very limited search, I’m still left wondering what it is that makes the Maine accent noticeably different from other parts of the Eastern Seaboard. Any ideas?

Good (if not slightly exaggerated) clips of the Maine accent can be found at the humorist Tim Sample’s website.

References:
Small, Larry. 1999. Fundamentals of Phonetics. Boston: Allyn and Bacon.