If he just started bowling, it probably better he start with a used one, but it depends on what they are. 20 years ago, most balls were urethane and plastic and many had pancake cores. Which balls do you have?
Thanks for the quick reply. One says "Angle" on it. The other I'd have to look again. I think it has 3 white dots on it.
There were several Angle balls 20 years ago, but all were urethanes with pancake core, except for one called the ultra Angle which had a dynamic core, somewhat similar to most cores today. There some more modern Angles made in the late 1990s, early 2000s, but if your balls are 20 years old, more than likely they're the urethanes. I believe almost all were solid colors, with maybe a couple of pearls here and there. You can check under the AMF brand name on this web site:
http://www.123bowl.comIf all your balls are older urethanes with pancake cores, they'd make a good spare ball or very dry lane strike ball. I'd suggest buying your son an inexpensive starter's resin ball.
The one with 3 dots on it is probably an AMF 3 Dot Classic, a very old rubber ball. It will hardly hook at all. Plus many drillers refuse to plug and redrill them because of the material they are made from - kind of unhealthy to be in the presence of that dust.