I began by scoring the outline of the oval into the bent side using an oval template--this way I could then Dremel away the interior up to the scoreline, and then refine my oval with files and sandpaper (shown above).
On the inside, I was advised to glue in a cross-grain patch to strengthen the side and to prevent cracks along the oval. I chose to use rosewood side material for the patch so it would look the same as the sides, but I also sandwiched a maple veneer (shown above) into it to create a little maple line detail along the inside edge of the oval side port (I would love to have bound the oval in maple, but found the procedure too difficult and risky for my first guitar).
I think in the next photos I had already cleaned up the oval a little--I'm saving the final sanding for the end:
Once again, here's a picture of both halves ready for attachment--notice the back kerfing has been notched to accommodate the back braces.