VC Defiant 1910 Damper Door Struggles

[Zender]

Moved to a new house that has two stoves (Defiant 1910 and Lopi) and I am relatively new to wood burning.
The defiant sits in the main living space and wow this stove is quite different than anything I’ve seen before. I’ve already gained a lot of insight and done some tweaking thanks to this forum 🙏. I am getting an understanding that these stoves have love/hate relationship in the community.
My current unsolved problem:
When I close/move the damper lever on the left, the damper door either goes fully open or half open. Never fully shut. The lever also doesn’t point to open and close markings etched on the side of the stove. Making me think that the linkage has come out of alignment. I cleaned around the damper door and found bunch of broken/stiff gasket. It moves freely now but still stuck between open and half open. I can also pull it closed with my hand by holding the screw in the middle
There’s no gasket now, but that’s the next project once I could get the door shut.
Is there a way to remove the damper door completely and realign the linkage? Am I not looking at this right?

 

[begreen]

The bypass damper plate could be slightly warped, or it may just need a little adjustment. Remove the griddle to observe its action.

Another possibility is that the bypass handle socket is a little loose on the shaft. In that case, it's a matter of tightening the socket's set screw.

 

[Zender]

The bypass damper plate could be slightly warped, or it may just need a little adjustment. Remove the griddle to observe its action.

Another possibility is that the bypass handle socket is a little loose on the shaft. In that case, it's a matter of tightening the socket's set screw.

The griddle is the honey comb in front of the secondary chamber? I see refractory at top side blocking the view. Should I just pull the refractory out?