Lookee what I found:
I uncovered two NIB urethane balls - both 16 pounds.
One is a red rhino, dated 1991 PBA Oregon Open Pro am ball

and the other is a purple Trackster 1992 PBA Oregon Open Pro am ball.
http://www.bowlingballreviews.com/ball.asp?ballid=191

The trackster is a pearl urethane, the rhino is a red dull ball with gold lettering and logo.

I would keep them and use them myself, but they're too heavy.
Make me a reasonable offer, or they're going on ebay...