18xx-S Seated Liberty Quarter Dollar - Last Two Digits?

Now that's nice! The overlay itself of the 1872 is a shade off but it does look like that isn't going to work, while the 77 seems like a nice fit. Great to see those dates to same scale and all as I didn't realize just how much curve there is on the top of the 7 and down the leg. It's not boxy at all. Seems like things are getting very close to the answer with these images.

I agree the overlay is great. What do you use? And did you align over the "2" on purpose so that the comparison of digit features would be synched?

I'm reposting previous closeup because I didn't consider manipulation earlier. But what is this "toning" stuff? The bottom edge of Liberty's base looks like how my trim turns out when I try to paint my house myself. I guess when there's a $995 value difference I start getting overly suspicious.

The purplish toning looks a lot like the initial color of silver test solution on a silver coin, though the purple color doesn't remain after rinsing. But acidic test solution does "bite" the coin surface and gives a permanent tan/brown discoloration with a slight etch. Addition of something else, such as iodine or a sulfur compound, could create the permanent purple stain. The presence of the yellow C in the field is strange - as if surface contamination might have interfered with the staining solution.

The staining is all over the fields of the obverse, but not on the raised features, as if it has been painted on. Seeing how the purple color has penetrated the crevices - between the dentils and into the surface scratches - it looks like the raised features have been buffed or rubbed to remove the color and appear silvery again.

This is an 1877 S Quarter. The other key to determine is the mintmark, on the 1872 there is only one reverse die variety and the S (and smaller) is centered over the "R". On the 1877 there are 11 reverse die marriages and none of them are centered over the "R".

Just my opinion.

That zoomed in photo of the date region convinces me this coin was doctored. Not only is the cameo effect unnatural (you can see where they painted on the oxidizer and smeared some a bit too high), but the date has been tooled and sanded down to conceal it. The 1 and the 8 are sanded almost flat along with the other digits to hide the modification and make a date of 1872 plausible. There is no way the coin would have natural wear of those digits all the way down, when the date is still protected by the rim and the base of liberty seated.

From the junk silver bin, it rises to tell its sordid tale again. This is what I love about this forum.

I have been learning quite a lot here, and wanted to thank all for thoughts and input. My sort of final opinion would be that this is an 1877-S quarter. Period. I can't see anything that can overcome the evidence for that determination.

That said, I don't believe that the hard stuff on/around the date was put there to do date mischief, but I am starting to believe that it was used for that purpose. The 18 are almost certainly sanded down, while parts of the other two numbers seem worked a bit to get them where they are. Originally I thought someone found a dateless coin and just removed stuff until they got the date. But now I am pretty sure that at least some effort was made to make the thing look as much like an 1872 as possible.

So from my end I believe it would be reasonable to call this a counterfeit 1872. Which would be great as I collect counterfeits and this would be a neat addition to that part of my collection.