None of the 3 Roch B's I have (2 in parts stash, 1 installed on a 216) have a hole anywhere on the drivers side of the housings and the area you descrobed is smooth with no hole.
All of mine are manual choke versions, I'm unsure about the automatic choke.
One of the B's in my stash came off of a 54 235, course the odd's it was the original are pretty slim.
