It is an interesting question: which evidence do we prefer, old accounts or contemporary practical advices?
Both have problems.
Old Persian miniatures, for example, are stylistic and do not provide details. Unfortunately, there were no digital cameras 500 years ago. Mark's example of a SE Asian painting with a clearly defined tip of the Daab is a nice exception, but even then we can suspect a certain degree of artistic freedom.
Contemporary masters did not live in a vacuum all these years either: new materials, new techniques, new market realities surely changed their products. And they learned their craft from the teachers who themselves were subject to the same forces. An example is the modern Caucasian kindjals and shashkas: enamel galore, easy filigree techniques instead of difficult and time consuming repousse, totally foreign ornaments. And I am not talking about the blades!
Their successors will not even know how to do the work right and will resort to even more freewheeling.
The most impotrant factor is the disappearance of the need in bladed weapons. They are becoming objects of art or just plain souvenirs ( witness contemporary Indian "damascus" creations). That is why contemporary bladed weapons become more and more "fantasy pieces". Going to the "native" country and looking for an old master in hope to learn reliable info about ancient swords is rapidly becoming an exercise in futility. He can do a nice job, but his main source of income will be kitchen knives, meat cleavers, axes, bazaar pieces etc. Aand he learned the craft from his father who were just in the same boat as he is now. I would be very hesitant to use him and, especially, his more distant descendants as a source of "academic" information,