1986 Jeep Cherokee XJ-Hot air actuator for manifold air

I have a failed vacuum actuator for the trap door in the air cleaner that lets the warm manifold air in during cold starts. None of the auto parts stores have this part. The OEM parts manual doesn't even list a part number. It acts like it comes with the air cleaner. Has anyone improvised a solution for this or know where I could get a working part? Any ideas maybe what other vehicle might have the same part that the part might be more plentiful? I attached a picture from the OEM parts manual with the part circled in red. It is about 2" in diameter and about an inch thick and rivets onto the breather housing. ...Thanks!