Very good find, and a very interesting gun. I had never heard of one, so I did a quick search. I will say you will find more information if you search Model II instead of Model 2.
You are seeing a wide variance in prices because obviously if it's a collector grade it will bring much more than a shooter or a restored gun.
The good news is (if you want to sell it) I don't see any for sale on GB, that's pretty unusual. I only see one in the sold items and the seller isn't really sure what it is. He calls it a single shot sporter or possibly a Model 2??