1966 Topps condition question

[nolemmings]

I have about 75% of this set in sleeves and then rigid holders, where they have resided for 15-20 years, in what appears to be nm or better condition save for some that are off-centered. I took them out to put in 8-pocket sheets today and noticed that about 40% of them have slight notching or crimping on the top or bottom of the horizontal cards. These are seldom in the exact same place, and are real hard to see unless you hold them at an angle to the light--which means they are likely unseen in most scans. I do not believe I came upon these all at once but I just don't remember. Maybe the prior owner mishandled them somehow, but the remaining condition (sharp corners) makes me skeptical of that. Anyway, I assume they would grade out at 5 or less because of the flaws, and although I am not a huge graded card fan, this bums me out.

Was there something in packaging or production that made this a common occurrence? I hesitate to complete the set or replace what I have with any non-graded cards at this point if they are going to arrive with these issues.
Anyone collect this set and have insights?

[Aquarian Sports Cards]

sounds like rubber band damage

[nolemmings]

Thanks for the response Scott, but they're not rubber band marks. Much more subtle, usually only on top or bottom but not both, and seldom near the middle where you would expect rubber bands to be used. One mark in various places. I wish I could hold the card(s) at an angle and snap a photo to show what I mean.

Suppose you had a stack of cards, placed the stack on its side, held tight with one hand while you "strummed" a coin down the stack. I imagine that little indentation would look about the same, only then the cards would have the flaw in the same spot--maybe if some cards were upside down they would be in the mirrored position. These are more random.

Just didn't know if there were known production or packaging problems that might have caused this, or something else. Oh well.