This touches on the subject. http://www.error-ref.com/rolling-mill-errors-rolling-indentation/ I'm no expert but the guys who contribute to that site are and are members here. Maybe one of them will chime in.
Your proof Lincoln cent error is likely worth several hundred dollars. I'd say around $500-$700 I would also advise getting it out of that stapled paper 2x2 and into something safer
@Hommer Thank you for the reference. The Rolling Indentation error seems to match really well with the example I have posted. The idea that the indentation was created before the actual striking of the coin makes the most sense. I noticed that @mikediamond is the Senior Editor of error-ref.com He has provided some invaluable information to me on previous threads and I would be thankful for him to chime on this piece as well. Again, thank you for that reference. The error-ref.com website is a great reference for me and I'm sure other members of this forum would benefit from the information on there.
@JCro57 Thank You for your comment. The 1980S proof Lincoln cent was most likely put into that stapled 2x2 in 1980, basically 40 years ago. At that time my father was working with other dealers across the country who were ordering proof coins by the roll instead of full proof sets. Back then there would be an employee or set of employees that would sit down and take apart proof sets from the mint and put the coins in tubes by denomination. This was done to the tune of thousands of sets. During that process different pieces would be put to the side as being below-average, problem pieces, or errors. This is one example of those pieces that was pulled to the side. The same story applies to the origin of the 1970S proof Roosevelt dime I posted. As you said, it probably is a good idea to get those proof pieces out of the stapled 2x2 holders. I would hate to have something happen and the staple scratch across the surface of the coin or something else happen. Thank you again.
Interesting Provenance ! Kinda sounds like you had a real good idea of what you had all along and you were just testing us....
To me the cent looks like a Proof, obverse looks like a major clash but for the 'marks' about the date and the nicks on the top edge. But the (clash?) marks on the reverse match NOTHING from the obverse, which makes it VERY suspect to me. The dime is a legitimate minor clip. The half dollar is a planchet error -- a void in the unstruck planchet that made a slight 'give' under striking pressure that made the opposite side strike more weakly in that area.