The "bumps" are small after 47 years? That's about as catastrophic as a few hairs growing from your ears or nose after you grow older. I don't think that there is anything to worry about unless there is a visible crack in the outer ply of wrap. A sawdust particle or grain of sand from the automatic sanding machine might have been trapped in the mastic used for adhering the wrap. I would not worry about it at all if the top ply is intact. But, I would use it as a bargaining chip if the seller is reluctant to lower his asking price. It's good negotiating practice (just as in political arguments) to use an insignificant defect to downgrade the item you want.