Hello,
The 31-pin connector is impossible to find.
Here are the Molex part number :
0039532314 : 31-pin, right-angle ZIF
0039532315 : 31-pin, straight ZIF
0520443145 : 31-pin, right-angle, non-ZIF
0520453145 : 31-pin, straight, non-ZIF
But, the distributors have only 30 or 32-pin connectors.
Regards,
Frederic