I have a 75" TV that I want to mount above a wood burning fireplace (don't worry, the fireplace is not in use!) in a 1920s built house. I have bought this pulldown mount from Monoprice (https://www.monoprice.com/product?p_id=27773). The weight of the TV is 79lbs and the mount itself is about 33lbs.
The wall is plaster and wood lath with brick behind. The brick is about 2.5in behind the face of the wall (plaster and lath about 1.75in and 0.75in gap).
Since the wall bracket for the mount is I-shaped (i.e. bolted across the top and bottom, I'm thinking to cut out two parallel channels in the plaster the width of the mount to expose the brick, fasten 2x3 lumber using anchors into the brick so it is flush with the wall, then attach the mount to the 2x3 using lag bolts as if they are studs.
Requesting feedback or other suggestions. Hoping to limit intrusion into the plaster or face my wife's wrath. Thanks
EDIT: Slight setback during the installation...the adhesive started gelling in the nozzle in less than a minute and my caulk gun broke. I managed to get some in all the holes (don't think the last hole was fully filled) along the top row and get the rods in place. Hopefully it's enough. Need to go buy a new gun to finish the bottom!