There are a lot of messages on this thread and I’ve not had the time to read all of them; just to say:
I created the latest version of the SVG and had intended to turn it into a working part, but ran out of time. If you have any questions about it I would be happy to help. I put a lot of work.into getting the layout right.
However, be aware that the pin alignment on the svg of the DF board does not match Fritzings Mega 2560 for two reasons: 1 the two actual physical parts are slightly different dimensions - they fit but there is strain 2.The dimensions for the 2560 part in Fritzing are wrong. I checked against the orginal.CAD files and I have a (modtly) complete revised 2560 part but never got that completely finished either.
Also note: DF change theIr boards a lot. Your work could very easily be wasted.