steve lyden brown

In common with member Bob M, I too visited such sites used as locations in "The Ladykillers" as I could find. This was about 20 years ago. I think that the railway bridge used to drop the bodies off still exists, perhaps because it is outside the area now developed as described by Bob M. Of course, in the movie this tunnel ( very near to Pentonville Prison) is immediately behind and only a few feet away from the house occupied by the Ladykillers, but I formed the impression that the house never existed on that site and was probably a studio set.
SGLB

Dave Rattigan

Yes, I'm pretty sure you're right that the house was erected especially for the film, albeit at the actual location rather than at the studio.