There are probably some involved
things here. We have an f(V)r-fr(V) cluster, and anticipation plus the
'articulatory gestures' involved make separating all the phonological goodies a
little difficult. What's the word. Not metathesis. Assimilation?
There is also the proclivity for
current day English to cliticize prepositions fore and aft. R-dropping here is
not 'non-rhoticism' but obedience to some other rule about how rapid idiomatic
American speech is to be done.
As for your Northern Illinois
accent. Chicago? Northern Cities Vowel Shift? Do you hear 'chopsticks' when
someone not of your dialect says 'ChapStix' (ChapStix is the
brand name of a lip balm).
In my dialect (Northern Illinois) we always keep the "r"
sound. In fact, a distinguishing trait of my dialect is to overstress the "r"
so much that it almost becomes vocalic, and changes the preceeding vowel to
@. We almost seem to say "frr free