Your pressures sound about right. Factory pressures do seem a bit low. Experiment and find out what's right for you. Agree with Spax, use on softest setting especially if they are the older type. Konis are a bit more compliant.

1969 4/4
1995 plus 8
1996 Plus 4 4seater
2002 Aero S1
2013 M3W
2014 Plus 8