And here's the base unit with all the stretchers. I'm planning on routing grooves for a pair of birdseye maple ply panels to enclose the sides. But first I'm going to make a 6 or 8 drawer unit between the upper and lower stretchers with a ply top on it for a tool shelf under the bench top. The drawers are going to be flush fit with maple drawer guides. Only with the drawer guides in place will I know how far back the ply panels can be placed in the ends.
The nice thing about mortise and tenon joints - you can put everything together each step of the way and make the next parts to fit the actual spaces already completed.
Here's an idea I'm considering for the drawers. Started with a digital image of the base with stretchers and, using PhotoShop, put in the drawers and the guides/drawer handles