There are a few flags for me, not that there is anything nefarious going on, but the person selling the Jeep did not disclose the issue in it in the ebay listing and told me about it after I contacted him by phone. Also they are not the original owner and said they just became aware that the heater did not work. His words were the heater core is missing but my guess is like Ole Rusty said it is most likely by passed. It is just a guess but I am thinking this person may have gotten the Jeep from the orginal owner and has not registered it in their name.
There is a reputable shop in the area that I called and they will do a pre-purchase check on the vehicle and give me an estimate for a heater core replacement I am debating whether to spend a little cash to get it checked out or just pass on it. My buddy is a diesel mechanic and said if they didn't bother to replace a broken heater core, who knows what else could have been neglected or hacked. I am going to give it some thought.