1921 Morgan D Edge Reeding Error

Hard to tell from these pictures, but I also detect some mushiness in the lettering, and I don't like the thickness of the rim in the northwest corner of the reverse.

Give it a bath in acetone first. The orange gunk on the back makes it a no-grade regardless.

Mass is 26.76 grams on certified jeweler's scale. The coin is just slightly larger than it's counterpart, I'm estimating it to be maybe .010.015 inch larger in diameter. I will spec it out in the metrology lab tomorrow at the university I attend. I am no seasoned coin collector but have had a small personal (pulled from circultion) collection for around the last 25 years and I knew I didn't want to clean the coin as I have been told that cleaning coins should be left to a professional. Thank you guys for your replies.

I've seen Morgan dollar with partial collar or railroad rim. But never seen one like this where the partial collar doesn't even look like it exist as if it was struck without the collar.
The 'orange' stuff probably just dried glue of some sort. Yes, acetone bath will most likely clear that. The coin itself looks genuine.
Why don't you post this coin in vamworld and see what their expert have to say?

If the composite and weight is spot on, it could very well have been struck with a plain edge collar. Perhaps an experimental strike of sorts, since they were transitioning to the Peace dollar. If it was any other date other than 1921 or maybe 1904, the experimental theory wouldn't be relevant.

I'm curious as to where this will land

Thank you guys for your replies. I have again verified mass at 26.762g in our metrology lab. As for diameter it is within +/-.0003 inch, thickness was +/- .00002 inch of all 11 of its counterparts. I would have to agree that with diameter, mass, and thickness being so close that it would have to of been struck in a plain collar. Why, or how is still a mystery. I can assure you that my great grandmother would have been the one to catch this error as she worked in a K.C. bank when it was minted. In addition my grandfater collected coins all his life and would not have kept a counterfeit. I know from talking to my grandpa about this coin as a child, that it has been in his safe since 1945 when he returned fron his tour of duty in WWII. When he returned from the war he purchased a house and a safe to keep war memorabilia and important documents in. Thats when great grandmas coin collection from 45' and back came into his possession. The others(45'-64') came into his possession after her death in 1964. I can understand the uncertainty or suspicions forum member's
would have of a coin variety nearly a century old just now surfacing. Heck, as I typed the last section I began to question my great grandmother and my grandpa! lol.