If you follow the spiral around it may show where it was scarfed end on. In theory, it could have been jumped on like it appears in the photo, it wouldnt be any weaker than any of the other spiral welded ribbands. It might have been easier to control the location of the transitition to make it up in two pieces like that. I believe, one of the writeups on Drew's site mentions making barrels of three tube components of varying thicknesses all jumped together.
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