An antique piano bench built by my great uncle around 1900 is the almost perfect coffee table. It's well made, in very good condition, and sturdy. It's Mission style which coordinates with my other furnishings. It's only functional imperfection is that the storage compartment under the seat can't be accessed if there's stuff on top. My coffee table always has stuff on top.
For a while I considered installing a drawer into the under-seat area, but I didn't want to cut up, drill into, or otherwise damage it. It does have a narrow board (aka stringer) between the two pair of legs that could easily support shelf.
After playing with the idea of a metal shelf with crenelated ends to mesh with the vertical slats and legs (I lack sheetmetal skills) and an upholstered shelf with fabric ties like a chair cushion (too "country" and maybe to floppy), the best idea popped: a shelf clamped to the stringer. I could do this! And so I did:
Here's the underside of the clamped shelf:
Here's what I did:
- Cut a board to fit, allowing about 1/4 inch for wrapping the fabric around.
- Covered the board with fabric (a reused piece of upholstery) using a staple gun. I avoided putting any staples where they could touch the bench itself to avoid scratching. See B in the pic.
- Cut two lengths of narrow board (or thick lath or rectangular molding) the same thickness as the stringer (A in the pic) the shelf will sit on.
- Screwed the narrow boards onto the shelf bottom so there was room for the supporting stringer plus about 1/4 inch. See C in the pic.
- Laid some felt (D in the pic) in the resulting channel. It was as long as the board and wide enough to wrap around the stringer A. I did the trimming after the clamping.
- Cut three pieces of 3/16 inch plywood (E in the pic) about an inch wide and long enough to span A and overlap the two Cs.
- Lined everything up, folded the felt over, drilled pilot holes, and screwed the three clamp pieces (aka E) to the two Cs.