Bug was first isolated thanks to the german FreeCAD contingent

Example SVGs are available in the ticketWith the change from 0.91 to 0.92 inkscape devs changed the conversion factor of userunit (uu) and mm. Pre-0.92 it was 1uu=1 inch/90 and starting from 0.92 it is 1 uu=1inch/96. This was necessary to meet the actual recommendations/rules of svg-standard and css. See article in inkscapewiki for further reading.
When a user creates a file in inkscape with absolute dimensions (mm) and saves it, then imports it into FC, bodies in Freecad come out with too large dimensions. For example - a 100mm square will be 106,66mm in FC now (100 x 96/90).