Supermatic: moving retard sector stud toward case increases (slows) speed; moving retard sector toward shutter center decreases (shortens) speeds. Delay pallet stud toward case slows speeds, toward shutter center shortens shutter speeds. Delay pallet stud should be at its travel limit toward the shutter center for the 200 and 400 speeds.

face plate attach 1: remove retainer screw, turn small circular lock with a flat side and two holes in it until flat is next to shutter center, push faceplate counterclockwise until tabs align with slots in in center of shutter then lift off. Installation is reverse of removal.
face plate attach 2: remove retaining screw from center ring, unscrew the center retaining ring by turning counter clockwise and remove, lift face plate off shutter. Installation: make sure face plate is clocked correctly and the pins and levers fit into the recesses of the under side correctly, install the retaining ring turning clockwise until snug then check the 1 second speed and the rotation of the speed selector ring. The 1 second speed should be .8 to 1.2 seconds and the speed ring should turn smoothly. Install the retaining ring screw into the hole that is in alignment or turn the retaining ring counterclockwise until the closest to aligned hole is in alignment.

I'm using standard manual terms.