Notes and conclusions:
1) There is not much "adjustment" to the shutter. Mostly one needs to make sure everything moves freely to get the speeds correct.
2) A common problem with these cameras is a closing curtain that moves too slow at the start and then too fast at the end. This makes one side darker than the other (right side in print).
3) There are more spinning and moving parts connected to the second curtain, so it is more likely to get held up. Even the synch contacts are moving as the second curtain rolls up.
4) Increasing tension on the second curtain spring only speeds up the end of the travel where it will overtake the first curtain giving less exposure to the dark side.
5) Decreasing tension on the second curtain (to keep it from catching the first curtain) makes it stick even more before it starts moving, giving more exposure to the light side.
6) Increasing tension on the first curtain, only slows the shutter speed (making the light side lighter) because the first curtain now moves more before the second starts to move. Increasing the initial gap.
The solution is to try and locate every spinning part attached to the second curtain. I used alcohol then fine oil at every spot I could fine.