This is a struck on a thick planchet error that I found a while back and I think it might be a proof that has went through circulation. I took pics of it next to a proof that I took out of the proof case. The edges are definitely proof-like and it has been in circulation for 60 years, so I think it could have lost some of its shiny appearance. I just saw that there was only one certified proof coin struck on a thick planchet on eBay and it says its the only one ever... it also has a huge price tag on it.
It's not the edge, but the rim you would look for in a proof. It should be squared. I can see from your edge photos the beveling you would see on a business strike. Sorry not a proof.
Looks like a business strike on a slightly thick planchet. It's about .1 g out of tolerance. Not enough to have a premium.
I found a 1909 gifted to me that i thought was a proof. It had 2 of the 3 look alike die markers. And I'm a great rim. Hoping some day it will devolope that 3rd marker. For your piece of mind. Try matching up that 58"s die markers. I don't think pictures will do it justice. Do a little homework. Even if its not. You will learn how to have all the answers why it is or isn"t
comparing a cent struck 60 years ago to one struck 47 years ago. Somehow I don't think that would be a good comparison. You need to learn the Die differences between a die created for circulated cents, versus one created and used for Proof cents. There is a major difference, which once know you would be able to identify a proof vs circulated strike.
here's some basic info ==> https://catalog.usmint.gov/faqs-faq...esign.html?fdid=faqcategory-products-programs ==> https://www.usmint.gov/learn/kids/collectors-club/coin-finishes ==>https://en.wikipedia.org/wiki/Proof_coinage
