The Ebay listing ends in 48 hours.
This is the rocket.
The rocket does not appear to come with fins, but does include two nosecones that both look a bit short for the King Viper. I think what you have is the fincan from the king viper, some longer body tube, and two shorter noscones. Still, if she sells for under $30 shipped, it would be a good place to start in building a huge 3 x 54mm cluster rocket.