Cross posted from another forum because only one person there had any idea.
I just go this coin from the 'bay, I bought it as what I thought what was a regular
coin indent error. However, now that it has arrived it is clearly something other than this, or a variety of this sort of error. Please take a look at the images and let me know what you think is going on here.
Obverse

Reverse

Indent Detail showing lip

Another indent detail showing lip

'railroad rim' showing partial engagement with collar

Another 'railroad rim' showing partial engagement with collar
