not a question, but I just want to share how I test fit footprints.
It's a combination of a few things to make it work perfectly.
The first step is to print a PCB mirrored on a piece of Paper:
PcbNew -> File -> Print -> Options Mirror -> Print.
2nd step: Take a needle and pre-punch all the mounting holes into the paper.
(For the large holes I used a hole punch).
3rd step: Carefully put the connector into the sheet of paper.
4th step: Take a picture or scan the whole contraption with a flatbed scanner.
This makes it easier to see small deviations than with the naked eye.
If you also put a ruler into the picture you can use that (or the known distance between 2 pins) to calculate corrections for the next iteration.
The trick is to print the mirror image. This will ensure that you can take a picture of the connector pins and the PCB layout in the same picture. See below.