Anyone familiar with that 1920s style mantlepiece that is about 6 foot
above the ground, about 4" thick, and used to have a coal burning stove
under it? The brickwork below it protrudes about 9" from the chimney
breast, and appears to have no function other than supporting the
mantlepiece.

I'd like to remove it, and the brickwork below it, so that just the
basic chimney breast remains (this would then be the same size as all
the other breasts in the house). I can't see that there is anything
structural involved but I'd be interested to hear if anyone has done
that thing.