The overall look pretty much shouts "transfer die fake."
Looking at PCGS photograde, I'd say about F12.
I'm guessing corrosion, meaning die rust.
deleted, double post.
Personally, I would rather use "collapsing die" instead of "die subsidence" as I think it is more descriptive and less opaque. Or to be brutal,...
Here is mine; I used axial light a few years ago to make the images which shows the color of the thin layer of oxidation on the surface.
Thanks for taking the time to post your report, I enjoyed reading it.
This one has a different legend on the turtle side.
I think you did ok. Looks nice and original. here is a link to a little history:
this is an MS64. The fields are reflective and color is accurate; scuffy slab though
Very nice looking coin! Quite a bit of rub on the rev, I'll guess AU50
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