At some point, and I am guessing later in the production run, the steering design was simplified somewhat. The earlier design used one-piece aluminum tubing and the later design used two telescoping aluminum tubes with a simpler connection to the under seat handlebar. The two piece design necessitated a clamp near the middle to lock the separate tubes after the seat adjustment.
(My#037 uses original design. #0136 Avatar uses the later design. I built my third bike ‘Orphan’ using the later design as it requires a little less machining)
**Duh… if this dummy had read the owner’s manual more carefully, I would have figured out that the cover page had the answer! Under the History page, the manual’s pages 1-16 (pdf) illustrate on page 8 the “new” steering. The cover page has a small entry at the lower right of the page: a o 0117. (Probably can be interpreted as “after order 0117” This would indicate these instructions were printed for all bikes after 0117.
Here is a picture of the steering on #066 submitted by the owner.
They appear to have made a minor change to the original design.