Agreed. There is kind of an awkwardly charming set of proportions to this fireplace. Maybe I would paint just the brick white and leave the panelling, it will contrast nicely after the brick is white. After that it could get a modern-y floating mantel maybe 8"-12" above the fireplace unit, right-justified with the unit but then extending all the way left (or stopping perhaps 6" short of the far left).

You could box the whole thing in, floor to ceiling, with a classic frame and mantle surround.

I really like the brick and would let it be. If you frame the FP and add dry wall, you can create any mantle you want, including shelving on the left. If not there is always whitewashing. I'm not fond of painted brick.

I find whitewashing to be great for traditional or cottagey looks .. this is a distinctly modernist fireplace and deserves a contemporary treatment . .mid century . . your furniture says you love contemporary things . . if I knew how far around the room that wood around the door went . . your black and white could happen here . .. white bricks, black wood recess . . black mantel right justified as detailed above . . if the wood only continues around the doorway, do it black too . . .but a stain if you can rather than paint .. .if it goes on .. evaluate after you paint the brick . . you might like to just use a polyshades on the recess to take it one step darker but still woodgrain .. match the mantle to that . .

The mahogany actually continues to the adjoining wall behind chair to the double closet and a staircase. Think Frank Lloyd Wright...Would like to update it with drywall, then paint same color as other side of room...grey. A real work in progress.

Remove everything from the ledge. Paint the paneling the same color as the walls. I would place a horizontal piece of artwork off center to the left on the painted paneling. Then add a couple items of varied sizes to the ledge ...more to the right side. I would not paint that brick!

My gut said no to paint and now that you have defined it as craftsman, I'd respect the FP and leave it. Could you add to the left of the fireplace a floor to ceiling 'bookcase', preferably custom, at least minimize the brick so you do not feel overwhelmed?

I'd not mess with the fireplace brick itself. Looks fine.

Definitely a mantel where the narrow shelf is -- maybe something about a foot deep that comes out about half of the distance of the hearth in front of the fireplace. I'd try to match the existing wood for the mantel.

I'd add a narrower board of the same finish flat against the ceiling between the existing board and brick to not come out beyond the existing board on the left . Leave the wood on the wall but maybe unclutter the look a bit.

You could add something attached to the wall above the mantel -- maybe metal art that would lay nearly flat against the wall or maybe a row of your favorite pictures (preferably in matching size and in matching frames) to create a rectangle on the wall above the mantel, being sure to leave room on each side of that rectangle to flank it with two of your favorite things atop the mantel.

You could put matching sconces on the wall beside the rectangle you create to flank it instead.

You could even hang something from that top board on each side of the rectangle you create, if not for daily display, perhaps for holiday decorations.