Recall that the main bulkheads have been tabbed, and that one of the issues is disguising the tabbing by creating a smooth transition between the tabbing and the wood. Fairing compound (epoxy thickened with low-density filler) has been applied and sanded. These are the red areas in the photos below.

Flaws are best detected after painting, and the bulkheads were painted with a two-part epoxy primer. The photo below shows the starboard-side main bulkhead after two coats of primer. The transition from tabbing to wood is nearly invisible, but there are minor flaws which will require additional applications of fairing compound.

Meanwhile, the engine bed was primed and painted, as shown in the next two photos.

Finally, the engine mounts were bolted to the bed, and the engine was (with considerable efforts) moved back into its original position.