So to put this to an end I stopped all the jobs I had in the shop to make a Fire Screen. I told my wife Elly I would just cut some plywood as a temporary stop gap until I could buy a wire mesh fireguard. Then I thought why not just make one from hardwood. I had some oak and some crown cut sapele ply left over from a previous project so I just knock together what is in effect a door without hinges. Construction is mortise and tenon joints with grooves to hold the ply in place. Finish is with shellac under ArmRSeal.
At the moment the screen is held in place with wedges but the intention is to have rare earth magnets in the screen engaging with some tiny, unobtrusive, steel brackets mounted on the brickwork.