I recently received a job for a simple chair repair through my upholsterer. This mid century modern chair was missing a front apron/stretcher, and had some other structural damage. It had also once been finished maple with walnut feet, but had since been painted black. The challenge was to shape a new front stretcher that would match the design. With no before or finished images to go on, I had to guess.
I has some hard maple on hand that was a perfect match for the existing material. As this piece was obviously factory furniture, the joinery was either dowels or keyhole hangers. One of the dowel joints had broken and required re-building. I drilled out the existing broken dowels with holes slightly larger than the originals, and replaced those with strong straight grained oak dowels, and then re-glued with epoxy (second photo). The front (and rear) stretcher / skirt is "joined" with keyhole hangers (first photo). The worst part of that system is that the hangers requires screws that go into end grain on the mating piece. I had contemplated driving and inserting a cross grain oak dowel to give those screws some purchase, but as the client was on a tight budget, I had to give that idea up.
The fun part was fashioning the missing piece. At fist, I thought I was going to work an arch on the under side of the stretcher, but after shaping the top side where it meets the curved underside of the seat (bent plywood), it was clear that keeping the bottom straight made the most sense. I applied a matching round over to the bottom edge to match the other parts, using a spokeshave and block plane.
With the repairs and rebuilding complete, I had to sand and re-finish the whole piece. That's when I found the nice walnut feet on the bottom of the legs (fourth photo). I regretted not being able to take the chair down to bare wood. So I re-painted it, then applied clear shellac, and finally a paste wax finish applied with 0000 steel wool.