Thanks for the info Frank, looks like by sheer luck I got the back thickness the same as the CRs. Tonight's installment is more top carving and body binding. After an hour or so more carving I got to the point where I was ready to finish cutting the binding channel. I have to wait until I have carved the bottom horn, because the binding follows the carve, leaving the exposed maple beneath the binding and above the mahogany. Here is the top carve about 90% done:

Now for my absolute least favorite part of building a guitar, especially when the maple is hard like this stuff is. I don't have a complicated rig like most archtop makers have, just a little stew-mac dremel attachment for cutting the arched binding channel. This process causes me more headaches and time than any other part of the guitar. I wonder if this "old-school" detail is worth it every time, and I have yet to be happy with the results. Here is the dremel attachment:

Slow passes are key, as the risk of tear-out here is magnified since the tool is hand held.

Thank god for old fashioned tools. I clean up the dremel route with super sharp gouge.

Next step is to clean the binding channel around the body with a little sanding stick and 150 grit.