Yep my original JYF drum sits in a hole and I've used tabs to fit in the rotor gap to hold it down (I store it on it's side). And I originally welded the pipe to the drum, the first time I did a small bead and I guess I didn't get much penetration. It eventually cracked and fell off. After that I put on a bigger bead and then some more. The pipe is probably closer to 3 inches instead of 2. Instead of welding in my tuyere I made an insert to slip inside the pipe.
What I have works well I'm just starting to make another one that's a little more compact, the grating for the tongs and hammers will swing up into position and my travel anvil will have a shelf underneath to bolt it down to while I'm on the road. I want to make sure I have the joint 'tween the pipe and drum done well because welding is a bit of a weak point for me at the moment. (practice, practice, practice).