I am trying to understand why a compound shutter is only firing one speed (fast, i beleive this to be the fastest the shutter will fire, about 100th of a second.

I have it apart, and found the timer weight was seized due to corrosion, which was easy to remedy. However, now the timer arm does move freely, the shutter still only fires max speed. I am assuming there is another spring missing on the cocking/firing lever?
Does anyone have any diagrams of this shutter?