I just got back late last night from the boat. You were right about the key that holds the cable in place. I removed the winch and backed out the key, with an allen wrench. I am still having trouble fitting the 3/16 cable into the hole.
I used a hacksaw to eliminate some of the thickness of the cable and was able to thread a portion of the cable into the hole and then pulled the remainder into the begining of the hole. I am concerned that the entire cable is not fully through the hole as it was when we removed it. We plan to screw down the key onto whatever cable is in the hole and somehow fix a portion of the cable around the winch so that is acts like a wrap.
Sabre has responded that it is the correct size cable for that winch, but funny they did not have your insight on the key. So thank you very much for your help.