Hi Thrifty,
Will you keep this thread going when you talk to buckleys as I too am in same position and would be very thankful to hear what has been said to you. It would save me repeating your enquiries. I'm also down the country so if you find a better located firm you might post that too. Seems to me that if supporting walls can be knocked through, with the aid of new lintels, then a fire place can be raised if we can only get a proven competant person to do it. Structural engineers would prob be better placed to comment on the fabric of a building rather than the state of the plumbing etc so I would still be in favour of getting one to check and specify the job before the competant builder starts.