The old G3 isn't really worth much any more. They are all over including Ebay.

You are probably not seeing the trunks, because it doesn't have any assigned. You can do a "list con all" like Dave said, or "li con carr or board 1a" and see the co trunk pack. The lines you have coming in can be used as CO trunks. They are more than likely just POTS lines. Set them up as ground start, and they should work.

Mike Jones
"A people that values its privileges above its principles soon loses both."
- Dwight D. Eisenhower (1890-1969), Inaugural Address, January 20, 1953