Are they yours? If not, where did you see the photos? On the 1967 set someone tried to obliterate the words "PROOF SET". Obviously they were made to hold coins but I've never seen them before this.
I have many coins that have been in holders similar to that which developed similar toning. It seems to be any of the old cardboard/plastic combination holders where you "push them in" that do that (over many years). Just speaking from experience.
Those Kennedy Halves are beautiful. IMO I don't think you could artificially tone a coin to look like that. (But some coin doctors can do anything).
They are part of a collection I am going through and selling for a coworker. These will end up in my collection. There are three sets in total and based on the collection these have probably been in the holders since they were released from the mint. Love the toning on not only the Kennedy's but some of the other coins as well. I may reload them and tuck them away for another 50+ years.
I have a 62 set in that holder that's a sixty vintage holder. It was a snap case plastic hinges,and two job catch in front. Yes that black cardboard did do a number on coins toning.
Yep, those are classic holders and well known to sometimes produce great toning. I've bought a few sets in those myself, even though it's not something I collect. If you can find one that was carefully selected, you can get some great coins.
