Just got my hopper, and I have to say I'm very pleased. It's heavy ass steel, not a triclamp ferrule welded to sheet metal. even the "rolled" edge is actually a heavy solid piece.
It looks like what they may have done is either welded a 10" ferrule to the large side and just filled in the gasket channel with weld then ground it smooth, OR they just welded a bead around the large side then ground it smooth.
It's very well constructed for just a hopper/funnel. My only complaint is that they used those god forsaken packing peanuts.... I hate packing peanuts they get everywhere and make a huge mess.
Makes fairrly decent hat as well, my neighbors sure got a show when I got out of my car with this on my head because I was carrying other shit too.