I have no idea how many may have been made but US patent #9,999 was issued to Thomas Warner, Chicopee, MA Sept 6, 1853 for a process of making "Twist" bbls very similar to this. According to his claims he took a solid bar, heated it, then twisted it like twisting a rope, to the desired abount of twist. It was then "Upset" end to end for compaction, after which it was bored to caliber, & finished to proper shape on the outside. This would definitely fit the description of a "Weldless Twist".

Miller/TN
I Didn't Say Everything I Said, Yogi Berra