Tom, the answer to your question in regard to the sewer tunnel is that it is located around the Phillip and Luce streets in Little Italy. It is on the map north east of the Corleone compound. Also, if you go to New Jersey and look in the railyards on the east side there are a bunch of crates, you can find a bum, who if you kill him will bring out a bunch of other bums. They drop cash. Be careful though, there's a lot of Stracci about.