On the reverse, upper part near the building's roof, on the left and right side there seems to be medal "drip" (or is that fireworks? )
Can you follow those lines all the way to the rim at about 11 o'clock and 1:30 (as I think can do from your first photograph of the reverse?) Maybe it is a retained interior die crack? Look forward to our experts' verdict.
They term clashes like this Monticello burning. You can see the clash on the obverse as well. Nice find!
I checked out Maddieclashes.com...I don't see one for your date. Have a second look and consider submitting photos to the site operators. Good luck! Similar looking, but a year sooner. ADC-5c-1988-01 : Mad Die Clashes
I can't see if those lines do go right to the rim LaCointessa....I will put it on the microscope again and look for that.
Don't waste your time looking for something i think i see. I'm no expert and defer completely to those who are. I'm reading now about die clashes again. It has been a while. Congrats on an interesting find!
You can submit your coin for consideration to be included on their website here: Good luck! http://www.maddieclashes.com/submissions/
Nice die clash. This happens when a planchet failed to enter the coining chamber. The two dies hit each other and leave impressions in the opposite die face. displaced metal, and it is metal not medal.