Here is a link to a Raduino replacement at easyeda.com
You can down load the Gerber files and possibly import to your CAD program. Or at least use a gerber viewer to print something you can get the dimensions off of. I have one I did up using a nano and a TFT display if you want. Only dimension that I worried about was the height from the bottom of the board to the right angle 16 pin header that plugs into the uBITX board. I made it a little longer to give mounting holes for the TFT board I used.
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DuWayne? KV4QB