Spacedeck and stylus force guage

Stylus force should only be measured in the plane of the record. On the mat and on a record are both too high. Try using playing cards to achieve the proper height.

I've taken measurements with borrowed digital gauge between off-the-record and off-the-platter and they were different by .03g so the pressure difference isn't that huge after all.

The pressure difference will depend on the length of the balance and will be different with different scales. My ADC changes by about .15G from record surface to the plane of the record and a friends Technics changes by about .09G. These both have a much shorter balance than the Shure for example so it may very well change less.