But perhaps someone will chime in with a better answer and information what were the standard factory heights of the pads.
There were no standard factory heights for front and rear rubber pads above springs. To determine correct heigh you have to use "Tabellenbuch". Height depends on few points:
1. "Sonderausstattung": extra ordered options for car like automatic gearbox, power steering, means you have to know how many extra options your car has, 1, 2 , 3 etc..
2. "Farbkennzeichnung der Federn" : color dotology/marks on springs from factory, ONE white, red and blue color mark on front spring (short, middle and long spring). To be found on
lower part of spring. There are also some color lines in the middle of spring but they are nor relevant. In additions to this on
rear springs you have one, two or three color marks!. Means: one white line is shortest spring and three blue lines is longest spring. Then you have a chart/table and by combining these information you can look up for correct heigh of rubber pads.
To be more complicated there are also 3 positions of rear spring plate which have influence on rear wheel camber
After 50-60 years you most probably dont have any signs of three colors on your springs so make it easy and go on with a heigh in middle of available ones.