We have an old house that we've been working on for a few months now. There has been all kinds of fun discoveries. Most of the discoveries are the really bad quick fixes that were made years ago so that it could be rented out faster. Luckily my fiance's father has been helping us all the way through with his know how and tools.
I had given an extensive answer for the sewer problem in another post without knowing you had clay tile. Clay tile is good stuff, it is used on my house in 1956 and still works fine; I jut have to keep putting the salt to it to kill the roots.