You may want to talk or email James Gates. He has started production of slugs that are pretty much duplicates of the Paradox. He's getting a little higher velocities from his loaded ammo than the old Paradox loads, but the slug style is essentially the same. He sells both the components and the loaded ammo. His company is called Dixie Slugs and has a couple of different slug types. One is the Terminator which was designed for rifled slug barrels, the Predator designed for smoothbores, and the Xterminator that actually bumps performance up a bit for rifled barrels.
http://www.dixieslugs.com/products.html

He's written about a few of his tests (interior and exterior ballistics) at http://shootersforum.com/
You'll have to do a search for posts by member James Gates. He's posted a ton of information about these slugs since beginning development.