Here's a little project I did a while ago, but haven't shared yet. Last year, I found a Lenovo Tablet folio case on eBay, it had a built-in keyboard and was going dirt cheap - the case had a regular USB connector for the tablet, so looked easy to repurpose. Here's the board freed from it's case, with a micro-usb breakout soldered onto the cut wire:
I laser-cut a new outer shell from layers of 3mm MDF at Access Space, Sheffield:
Then put it all together with a braided micro USB cable, and glued two little rubber feet on the back:
It worked pretty much out of the box with Linux (Rasbian) including the optical track point for the mouse. I did have to remap some keys to get Ctrl to work, and I added a custom mapping for the Function keys across the top. The result ended up being surprisingly thin, thanks to the very low profile of the keyboard from the folio case.
Q: Can I get the designs?
A: No. I have no idea where they are, and this was a very much a one-off project. Hopefully it gives you some ideas though ;)