If one of the door arms is broken, the actual arms are available from Omix-Ada.
There are at least 2 different ones depending on which one is broken. Sometimes you can put a screw in it to keep it together depending where it is broken. Here is a post with this reference in it. Hopefully you won’t have to take it all apart to replace the door.
"The first picture is the vacuum line connector. The one with the plastic actuator levers shows what you need to fix your doors. The one in the bag on the left is obviously shorter than the one on the right. It goes in the middle hole and operates the upper vent above the radio. The longer one goes in the top hole and operates the windshield defroster. They can both be ordered from Willys Jeep Parts, Jeep CJ Parts, Jeep Parts, Jeep Accessories
. Search for "HVAC levers" and you'll find them."
From this link:
Also some good photos here:
Vacuum arm replacement