Well Steve, I'd have to say that "Chink" is pretty offensive, certainly more than "Gerry" or "Eyetie" or "Brit" (Is "Brit" offensive?). Still, considering the historical context, I think you're almost bound to use the word "Chink" if that's the word that was originally used. I think it's horrible if we're forced to make historical accuracy subordinate to Political Correctness.
I don't use offensive terms in ordinary speaking and I will delete them from songs when they're not necessary, but I think you have a situation here where accuracy is important.
An example of where I will change a word is in "Shortnin' Bread" - I say "two little children," not "two little niggers" are lyin' in bed.
-Joe Offer-