The seams sometimes seen on the spine of wootz blades arrive there in three ways; they can be caused by porosity on the top of the ingot that gets stretched into fissures or cracks as the ingot is forged into a bar, they can be the remnants of a slight depression in the top of the ingot that is not removed in the forging, or they can be a sign that two or more pieces of wootz were welded together or welded onto a piece of core steel. The artisans of the time considered these seams flaws, though you do sometimes see them on otherwise nice blades. Although wootz was not ‘folded’ in the sense that pattern-welded material was folded to get layers, they would often join two or more pieces of wootz to get a sword-sized bar of metal or in latter days to ‘dress up’ a bar of plain steel.
Below is a photo of an interesting piece of metal (Thanks Artzi!) that was lost or discarded immediately after the welding process, an ingot of wootz cut in half and welded back on itself with a third piece in the middle, probably to increase mass.
The above blade looks like wootz to me, and not sham – you can see a ladder rung in one photo, did they put the kirk narduban into sham blades?
(I know, one rung does not a ladder make
)