Your 2004 needs the shorter version. On the 03 and up TJ's the seat belt receiver attaches at the side of the seat. The earlier models it connects at the seat base. You can access it by removing the center console or taking the seat out. I'm pretty sure it is a T-50 bolt. The part is available new or used. Ebay, Quadratec, Seatbeltplanet, all carry them as do others. If it is just the grey plastic surround that is loose and sliding down that is an easy repair. It is just held in by a push in plastic plug. You should be able to find one at Ace or your local hardware store.