If all permanents are on the battlefield, Seat of the Synod becomes a 0/0 artifact creature due to March of the Machines and dies as a state-based action.
Untap Salvaging Station with Seat of the Synod's death trigger.
Activate Salvaging Station to recur Seat of the Synod to the battlefield.
It's a 0/0 creature and dies to state-based actions again.