TJ question... Sentry Key system

Just picked up my first 04 TJ and aside from some surface (non-penatrating rust) is in near perfect condition. The TJ has removable doors, no wiring TO the doors and the keys are reminsent of the older Jeep keys, without the sentry system to the key. With that said, the 04 TJ is 21 years old (9/15/03) and has had two owners. The second owner treated the Jeep very well, garage kept, maintenance performed etc etc. However, the iginition key does NOT match the door key. While I can get the iginition re-pinned, I wanted to be sure that this did not come with the Sentry Key System. Is there an easy/obvious way I canm determine if it was born with the system and was changed at some point? TYIA.