Man, I really am going back to the beginning … seven years ago I got my first Mamiya Six.
I did some exterior cleaning … internal view/rangefinder cleaning … got knob … then I put it on the “collection” shelf.
Ok, so I decided to pull it off the shelf and take another look at it. Figure I should check out this flash delay mechanism on top of the shutter … hmm, not much to it but not the easiest thing to understand.
Two screws to take of the cover .
Hmm … no comment.
Things move but I am still not sure what it is supposed to do … oh well, put the cover back.
One of the things in my reassessing is that the shutter is not working at lower speeds. Back when I first got this camera I did not have the knowledge to understand how this shutter worked so I just could not fix it … now thanks to https://learncamerarepair.com/ I now know.
The NKS-Tokio shutter is a Gauthier type shutter.
Ok, so opening it up … unscrew some stuff on the front.
Firing the shutter I can see that the star wheel is not engaging the pallet smoothly.
I noted the spring that pushes the shutter was not sitting right under it’s shouldered screw thus impeding its tension. I took that apart and seated the spring correctly.
Ok, so now the slow speed escapement needed to be removed and cleaned.
This is when I found that the pallet lever was not attached properly, so I took it apart, cleaned it and secured it back on.
Now it engages the star wheel without sticking.
Put it all back together … fiddle with the positioning … now I have the slow speeds back to expected levels.
When I got this camera I knew that there was a missing part.
One of the spool securing knobs was missing. Lucky for me a friend made me a new one
I finished the knob on my Unimat with exception of the knurling.
This Old Camera 
Excellent. I have a IVB and I love using it.