Well, I figured I'd work on the back of the panel and the frame, probably finish both, then move to the front of the panel again and focus on finishing the painting.
What have I done?
Well, I used a Dremel and wood chisels to cut two recesses for butterfly braces in the back of the panel. One of the recesses has a walnut butterfly glued in place. Linen canvas pieces have been glued into the other recess and along the crack in the panel. At least that's where they are on the original. My version has a crack in the top of the panel too, but about an inch or so to the left of the one in the original. Unfortunately, the bracing location doesn't stabilize the crack in my version at all, but I'd rather be true to the original.
I also replicated some of the markings on the back of the original panel. The H and the number 29 are done with conte crayon and pencil, respectively, as well as the la Jaconde hand written script at the top left of the back. There's a red stamp inventory marking on the lower right that I created artwork for and had a rubber stamp made. Then it was a simple matter of stamping the image on the back of the panel. There's also some printed text near the butterfly recesses. I Photoshopped artwork from a scan of the back of the panel and printed out the text. Then I soaked the paper in strong coffee and dried and cut the strips to glue in place on the back of the panel. Once the glue dried, I used an Xacto blade to distress the paper to match the original. I'm waiting on the delivery of 2" wide white gummed paper tape to adhere around the edges of the panel and rip and distress accordingly. The addition of the tape and drilling insect holes in the back should just about wrap up the back of the panel.
The back of the panel was previously aged using a strong tea solution as well as a solution made from soaking steel wool in white vinegar.
For the frame, I bought 23K gold leaf and applied it to the previously stained frame. I had also applied a thin irregular coat of red bole under the leaf. I used water gilding to attach the leaf. Once the frame was completely leafed, I used steel wool and a burnisher to scrape and wear away the leaf to match the original frame. Still working on that. I printed out photos of the real frame to guide me on the antiquing. The photos below show the aging process so far.