Are the small crowns beside the Imperial Eagle on the tubes ahead of the flats? Would there be a "S" below them and is the 6 of the "6/31"?

Another observation is that an example in the assembled/completed/final state stamped with a "Crown" over "B" usually has a single Barbarian on one of the tubes and a single Barbarian on the flats.

Kind Regards,

Raimey
rse