Thank you for bring up this topic Michael.  Thank you Ibrahiim, your links were of great interest to Me. Most informative was:  
http://www.penn.museum/documents/pu...9-2/Cammann.pdf page 28, describes the triple ribbed blades being of a different steel  and perhaps,  that they are an older style. I did not find anything more.  We discussed this one here: 
http://www.vikingsword.com/vb/showth...ghlight=dharia
Does anyone know of additional info on blades from the Ansab area? or other examples?
Thanks, Steve