I've discovered that one of the chimney breasts was removed at ground floor but not supported where it met the ceiling/floor above. Effectively just hanging. There is a steel beam supporting the front edge of the chimney breast in the loft when it was converted (at the top of where the photos were taken). I have taken a few of the bottom bricks out to get a temporary support in (wood). Building control (Bristol) haven't been particularly helpful so far in what steps I need to take to remedy this but I believe I need to pay for the privelidge of applying to repair something that has been that way for years. I want to use gallows but don't want to proceed and then be told I need a beam spanning across the supporting walls. Do I need a structural engineer, party wall agreement etc. Neighbouring chimney is complete.