Due to the way we did the lap joint, the bottom pieces were not all of a uniform length in each direction. A quick cut against the fence on the tablesaw fixed that.
Check out the fit of the feet, and how much extra wood we have on the long board, and how short the short one is.
At long last, it's time to glue he bottom into the sides.
We need a walnut facade on the outer edge of the bottom, as that part will be slightly visible. We cut a notch into the end of a narrow board, and then cut off three and a half inches.
The facade is clamped in place, and a hole is drilled for a dowel. Endgrain isn't good for gluing, so a dowel is needed. A single dowel should be sufficient, as this should not bear any load.
Glue on the facade and hammer in the dowel.
Cut off the excess dowel, and plane the joint smooth. We used the tablesaw for this one, but that was too much of a hassle, so my dad planed the rest of them.