The 39-031 and 39-032 EntryGard (Caradco 916) operator is what I have. Is the central gear (in your picture available separately?
A handy person from Robbinsville, NC says:
July 20, 2014
Actually, mine is NOT an EntryGard item. It is a Cardaco operator. I notice that the length of the short arm is not exactly the same. Mine is 3 3/4 inches versus your 4 3/4 inches. Is there a 3 3/4 inch variety available? I have attached a picture of what I have.
Paul from SWISCO responded:
July 21, 2014
This looks more like our 39-155. I'm afraid the gears are not available by themselves, nor could they be repaired. If yours is damaged, you need to replace the whole operator.