I found some old Banjos of my grandpas and im wondering what their worth?

I found an old banjo called a Norma. At least from the 70's if not older. Then I found a Banjo called a Bacon and im sure its the same age or a little younger than the Norma. Alot I found a gibson four string guitar which im uming is a tenor guitar. It was Gibson on the headstock in jewels of some sort and is extremely old. Anyone know anything?