@CaptHenway I have a fun question. Why did you choose AU-58 instead of AU-57? Or AU-57.5?
I had previously chosen MS-63 because it was more than halfway between MS-60 and MS-65, and I wanted the new grade to be significantly better than the 60. Conversely, I went with MS-67 because the MS-70 grade looked virtually unobtainable, so 67 did look obtainable and besides it gave me two two-point steps (63-65-67) and I liked the symmetry.
Therefore, 58 was significantly higher than 55, and closer to 60 than to 55 but just not quite there.
I always wondered what numismatist would be bold enought to claim they "invented" the Au-58, MS-63, and MS-67 grades. CaptHenway is to be congratulated for this important contribution to our grading system! When I learned how to grade there was only MS-60 (uncirculated) , MS-65 (choice uncirculated), and MS-70 (perfect uncirculated); but MS-70 coins did not exist!
We did not anticipate grading modern coins, and modern commemoratives issued in capsules and American bullion coins did not exist yet, so "MS-70" coins probably did not exist when I rewrote the Mint State grades.
Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
Comments
We did not anticipate grading modern coins, and modern commemoratives issued in capsules and American bullion coins did not exist yet, so "MS-70" coins probably did not exist when I rewrote the Mint State grades.
But "Proof-70" coins did!
https://forums.collectors.com/discussion/1101864/the-first-70-coin-ever-certified#latest