Hartford type shocks

[Stutz in the UK]

Hi There, Does anyone have any instructions or ideas on adjusting Hartford type shocks

These are the type with the round friction discs held between two metal plates and then with two arms to connect them between the axel and the chassis

I have a set of these attached to an old car (1917 Stutz) and I would like to set them up properly

I have taken them apart and greased them up (they were fairly dry), to adjust them its a matter of tighting up the center nut, but how much?

Thanks