This thread got me remembering that when I was growing up in R.I., the Chinese restaurants always had the best Italian bread (which was kind of tough since restaurant choices were Italian, Italian Italian or Chinese). The popular story was they all had the same supplier and it was one of their biggest draws. I was shocked later in life to discover that Chinese restaurants don't always have bread.
So tripping carefully down memory lane I ran across the following recipe that sound alot like the version of (B) I grew up with http://www.pagesintime.com/ri/native.html
(scroll to the bottom of the page). I recall seeing Oyster Sauce as the primary sauce ingredient in recipes when it was still popular, and my Dad always called it corn starch gravy, so this looks like it's on track (but the measurements are wacky).
I usually got chop suey (as most restaurants served little bowls of the fried nooodles, duck and mustard sauces, along with the bread, butter and tea when you were seated) but if I recall the chow mein was frequently a little darker colored (soy sauce?) and, yes, served on the noodles.
In the early 70s we became quite sophisticated, foregoing chop suey for Moo Goo Guy Pan and anything on the Polynesian side of the menu with Lychees.