Mouth house (hum.. is it really his house or job a place where his father works ?) is located at 32 Skyline Avenue and was built in 1964 and has recently been sold. Check out this link for more infos
I was lucky enough to have been inside a few times and it was amazing to « be » Mouth for some pictures :) I was amazed by the fact that almost everything have been the same since the movie !