1976 Bicentennial Quarter Smashed Drum Error?

@MO, interesting coin, the right arm looks pretty much ok to me, but you are right about the drum. It doesn't look like a hit to me, but could have been preferentially worn there by someone who was bored. It also seems like a pretty large area to have been obliterated by die polishing following a clash. More likely, it may have been that some grease got into a pretty broad area of the die. I'll be interested to see what others have to say about it.

Remember the die is reversed image. The drum area is incused deeper into the die so polishing wouldn't do this. Either it is damage after mint(wear?) or in this case is a Grease Filled Die. a glob of gunk was in the device crevice on the die.

I agree it is a Struck Through Grease error. (a lot in this one) Note also the stick on the right is wider, so some was also in that device. If it was die polished, all the devices in that area would be thinner. The grease prevented the die from forming the coin in that area.

Is it worth getting the coin graded?

Not worth having it graded. They would just consider it as a normal coin.

but no, not worth grading

The Gem silver proofs are only selling between 6 and 10 dollars.
The grading cost would far exceed the retail value.

to the Community, Kingfish01!

Guess what? These are both from the same die pair. How do I know? The mint mark locations on both coins are the same.