This area of the blade appears to have been focally cleaned with acid. In this view the four central bands on this face of the blade appear as patterns with nearly parallel diagonal lines. The upper two bands each display a clockwise twist as does the bottom band. The third band from the top has a counterclockwise twist. As there is considerable loss from corrosion [including the acid treatment], these areas of pattern appear to correspond to the inside surfaces of a flattened strip of twisted composite rod (which would be welded to a non-patterned base or to the pattered strips of the other face of the blade). It is interesting to speculate that the smith may have mistakenly used a rod with the wrong direction of twist in the upper position.