ScottH, I was just wondering the same thing.
I guess you could fit a chunk of steel to the barrel, then carve away those parts that don't look like they belong. Then drill a hole in chunk, a hole in the barrel, then line them up and weld it on. Then one could drill a hole for the nipple that hits the hole into the barrel, and thread for the nipple. Just tossing out ideas - I've never encountered someone making their own snail.
Runar, what say you about the snail?