I started out with a 25" TV as seen in the picture below.
The doors on the overheads on either side of the TV are 32-1/4" from door frame to door frame. I didn't want to slice anything off of the frame if I didn't need to. I also thought about filling the hinge holes and relocating the doors slightly outboard. Luckily, I found a Sony Bravia 32" LCD with an overall width of 31-1/2" so everything worked out dimensionally.
I built the frame/mount out of Poplar. The frame actually looks somewhat like a ladder. The front face of each side board of the ladder are cut at 45 degrees. This allows the TV to mostly sit within the framework. The two cross pieces behind the TV are 1 x 4 boards lying flat. They are used as the mounts for the TV. The TV required four M6 screws to hold it to a mount. The TV also had two 1/2 O.D. by 2 deep holes molded into the upper rear case of the TV, slightly above and outboard of the upper mounting screw locations. I utilized these holes to actually hang the TV on. I drilled two 1/2 holes in the 1 x 4 and then glued two small lengths of 1/2 dowel in the 1/2 holes that I drilled into the 1 x 4. I drilled clearance holes for the four M6 mounting screws in the upper and lower 1 x 4's. I drilled three clearance holes for a #10 screw on each of the side frames and counter-bored each hole to accommodate a 1/2" domed plug. I used these holes to mount the TV and frame to the plywood side walls of the overhead structure.
I modified the plywood side walls of the overhead structure by cutting it back by about 4. Next, I cut notches in each of the plywood side walls of the overhead structure to accommodate the 1 x 4 ladder pieces. After all of the cutting I slipped the ladder in place. I used a transfer punch to locate the position for the mounting holes. Then I removed the ladder and glued 2 x 2 x 3/4 backup blocks to the plywood side walls of the overhead structure inside walls directly behind the position of the mounting holes. After the glue dried I drilled pilot holes in the plywood side wall of the overhead structure.
By cutting down the sidewalls on the "box" by about 5 inches the face of the TV was set back about 3 inches from the original design. It does not protrude into the living area as far as it did.