Jeremy - I'm also a fully paid up member of the MCS (Marlin Contortionist Society)
That's how I put my old metro servo in, and out, and the test servo in (and out) and finally the permanent chrome servo. Call for the osteopath!
As for the clevis on the input rod, I left the nut on there and used it to lock against the clevis once it was adjusted correctly. There's not much chance of the clevis unscrewing once it's either side of the pedal, but I reasoned that its an extra set of threads to exert the pressure against.