1875-CC Dime

Indeed it is. I think it would have to be graded AG-03 - the reverse is just too far gone.

G4

Sorry - no matter how nice the obverse looks, there are no discernible rims left on the reverse. This would never make G-04 at a TPG.

If anyone can cite a photo grading reference that shows a G-04 that looks like this, please advise!

Its a split grade between the obverse and reverse IMO
I also don't think it much matters what a " TPG" might say as much as it matters what known grading standards are and certain points that can be made debatable.

My best guess is an F-113 die marriage due to the MM location and potentially a weaker strike on the reverse over O(N)E D(IM)E that has been exaggerated by wear. Reverse G, seen on F-111, degenerated on those exact reverse areas of "one dime" so its confusing to me on the reverse die of your coin as the MM does not match up with Reverse G but Reverse I. Would the reliefs suffer weaker strikes as the die degenerated further? Could be. I'd like to hear from some experts regarding that.

I have noticed that Lib Seated coinage, like Barber coinage, tends to wear faster on the reverse than the obverse. I don't know why that is the case, but I sure do see a lot more split grade coins than other series. My personal opinion is G4/AG3 split grade.

Why did the industry do away with split grades / net grade anyway? It was, to me, a very useful system when ANACS used it in the 80s. You could send a coin for a photo-certificate/authentication and it would come back as something like MS63 obverse / MS61 reverse, net MS62, or whatever. They did that for details coins, too, you could send in a MS coin with some sort of issue and it could come back as MS-63, issues, net EF-45. This gave dealers and collectors an approximation of how much to devalue the coin to compensate for the severity of the damage or issues.

Way too much wear on reverse for a good. AG-3