This is going to be a picture heavy post, but I want to wrap everything up once and for all. Scroll to the bottom if all you care about is the "after" photos! :)
So here is where we last left off, with a bulkhead along the top (so the shelves will have something to attach to) and the top of the mantel installed.
Next it was time to install the bottom side of the mantel. And again, we used blocks of 2x4, to give us something for the underside to attach to, spaced off of the ledger board. This is because we wanted to leave a hollow space in the mantel for running our TV cables.