Double Reverse Coin Found, One Side Roosevelt Dime Other Side Memorial Cent

@PC, first welcome to CCF. Second, that is an interesting piece that you have there. As correctly noted by @coop it is a so-called Magician's coin. We see them posted here on CCF several times a year.

What I find interesting is that it appears as though the method of manufacture has changed over time. More specifically, it is my observation that your type, where both coins had one side ground down and then the two halves were bonded together seems to be the "old" method of manufacture. Typically for combinations that include a cent, we see them with wheat cents. The "new" method of manufacture is to hollow out one coin leaving an intact rim and then fitting into the remnant chamber a slightly undersized second coin. Brand new Magician's coins that you buy on ebay are generally made this way. Of course, I haven't studied this seeming progression in manufacturing method, so maybe it is nothing. In any case, I'm glad to see that you have found one of these.

I never meant to imply that the coin was a genuine error, that it was a fake, or that anyone was correct or incorrect in their opinions.

My point was to point out that the OP submitted two, frankly poor, photos of an unusual coin and that opinions concerning the nature of the coin based on those photos alone were suspect because the photos didn't show nearly enough to support those conclusions.

Alteration of the coin after leaving the mint is the most likely answer and a Magician's coin certainly seems to make the most sense, but I still think better photos of the item to be sure is warranted.

Had the OP taken the advice of the first few posters he might have disposed of the coin prematurely, and that's something we should be trying to avoid happening.