Although on Staten Island, I believe that in the film, the house would have been in Long Beach, Long Island. Is that correct? I base this on Michael's call to the house when his father is in the hospital and the exchange was LOng Beach.
One more thing about GF1: When Michael is being driven to the sitdown with Sollozzo and McClusky at Louis' Restaurant, there's a scene where they're heading first to New Jersey (before the U-turn occurs). What bridge is that? The George Washington over to Fort Lee?
For those interested, Godfather 1 scene locales HERE