Pictures would definitely help. However, it might be difficult to to attribute with any certainty without seeing the piece.
Unfortunately, pieces attributed to Poli abound both on the Internet and in some stores. I'm in Vancouver, B.C. and I regularly see pieces attributed to Poli that the seller can't provide a reasonable explanation of why he (it's always a he) thinks it's Poli.
Your best bet is the store where you bought it. Do you trust the seller? Is he able to give you a convincing explanation of why it's Poli? Convincing to me would be reference to an authoritative book, which pictured the same piece, or the same from a major auction house, such as Dr. Fischer. Not convincing would be eBay, an Internet auction house, and "I've see a lot of Poli and I'm sure this is one."
$1100 doesn't seem a lot for a Poli, but it's certainly enough to make you want to be sure that you're getting the genuine goods.