The cent folder was probably made around 1963ish, there are mintage numbers printed in it before that but none after, they probably printed the dates in anticipation of nothing changing, not knowing there would be no mintmarks between 1965 and 1967.
@Shrews1994 PM me which ones you need to fill holes and your address and I’ll try to get them out to you when I go to the post office tomorrow (free of charge). I found them all CRHing, so they cost me 5 cents. My only request is when you upgrade them, that you regift them to someone else and spread the joy and goodwill in coin collecting.