I'm excited by all these "in service" projects. I realize that this is not a forum for soliciting sales, but I hope all "you people" know that I want one if you make them, I want one!
Now here is my diatribe of input....
I would suggest adjusting the configuration design in the book slightly to fit the PADD, as opposed to changing the PADD to fit the book. I think that it's most important for the PADDs overall outside look and dimensions to conform (with some wiggle room obviously) to the familiar prop we all love. For the same reasons, those oh-so-familiar iso chips have to be the "right" size. So I would certainly draw heavily on the book diagram for design influence on the interior circuitry, but still adjust so that already familiar elements stay true.
I've given this some thought, probably since the book came out originally. You could probably work it for a single chip across the body, instead of two as illustrated, and to add more depth to the circuitry inside of the padd so it doesn't look "flat" is have a single chip above, and two chips stacked on top of each other below. That would be in lieu of the chip illustrated on the front side of the PADD, the front would just have a pocket for the chip to seat into if the padd were closer. In concept it could even still be a chip to control something on the front casing, heck, add graphic or tape detailing to illustrate contact points or an interface. Plus, stacking the chips will create a neat layered look. I also recommend using a mix of media to make it look like there are as many different components to this thing as possible. I don't mean clutter up the design, but use elements of graphics, of physical tape detailing, perhaps etched parts, and combinations of those on plexi or even on top of each other to create more illusion of depth and functionality.
A lot of these ideas can be seen in the padd photos below. One is a build by Chris Avilla that I love (sold on eBay at one time as I recall), and the other is a PADD in my personal collection made by a guy named Mike Walston. Half way showing off, but you might draw some ideas from these.
Here is the padd made by Chris Avilla. He stayed fairly true to that design from the tech manual, but still made it his own. I like parts of what he did here, most notably the intricate tape detailing on top and below the plexi detail on the back panel behind the main view screen. Only criticism is hat I wish some of the printed graphics were a little less simplistic. This padd was meant to be displayed open, there was no practical way to close it.
This one is made by Michael Walston, who has long since disappeared from the scene. This padd closes and holds together with magnets. This one is really neat because it combines so many different materials for the detailing. There is laser etched plastic, etched metal plates, chromed plates, etc... I also like how it adds dimensions with ridges and crannys and different pockets and compartments. All just adds to it being more "real and functional."