It is from the territories controlled by the Teutonic Order, the Latin equivalent of which is presumably what "TO" stands for. 1/84 gulden is correct. Do a Google image search for
Teutonic order 1/84 gulden and you'll find several coins that look like this, though with different dates. Coins from this state smaller than 1/4 thaler are not listed in my 4th edition Krause catalogue, but they are listed on the
NGC database.
Krause lists it as made of copper, but all the pictures on Google Images are silvery-brown in colour so I suspect it is actually made of billon (debased silver), as many German States coins were.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis