The 'Bicycle Mechanics' section was probably not the best place for my question, so I'll try asking here; sorry for cross-posting.

It's relatively clear when to add the tension, but I've never seen any information about initial setting... Currently I'm trying to restore old leather saddle (from soviet racing bike, almost exact Brooks clone), and highly appreciate any recommendations on this topic.

Is there anybody with full saddle overhaul experience? How do you determine the amount of tension to be set on just riveted one?