Last week I finished the tub for my book press. My woodworking skills haven't advanced much past the 10 year-old Boy Scout stage, but I'm pretty happy with the result. I didn't have the proper size bit to drill pilot holes, so I ended up splitting the wood when I drove the screws in, and the outsides of the rails are a bit chopped up, but the functional bits should all be fine.
The tub is basically just a box with rails. The actual book press will sit between the rails, with one section sliding over the top, which has been sanded smooth. I should be able to complete the press as soon as I find some hardwood in the proper dimension.
Overall the tub is about 22" wide by 11" deep by 8 1/2" tall.