Oiluj13,
Than you for your continuing pursuit of this blade's structure. I do have a couple more ideas. I suggest that you look at the
Knife Steel Nerds online site. Larrin runs the site and is an excellent resource on knife steels--he is a true scientific expert on the subject. I would recommend becoming a member of the site (it's free). Larrin has responded to my questions and is very helpful.
I'm afraid I can't comment on your latest data. The blade has a lot of surface pathology (grind marks, oxidation, etc.) that prevent me from interpreting much about its composition. If it were my knife and I wanted to know mor about its steel I would grind out all the marks and polish it back to white. Then I would do some controlled etching with a variety of solutions to determine which one best showed the crystal structures and other features.
Nital is a good etchant but hard to get unless you are an analytical chemist or academic (and it can also be explosive in sufficiently high concentrations). Ferric chloride solution is quite good and I start at a 1 in 10 dilution of a commercially available solution from Radio Shack, moving up to 1 in 5 dilution if necessary. It is acidic and stains skin and clothing, and any surface it contacts!
Vinegar is okay bit often slow. Citrus fruits are also fairly slow and the pH varies widely making a controlled etch harder to achieve.
Only after a complete cleaning and etching of this blade, with observation of the surface under a microscope, would I venture an opinion on its crystalline pattern.
The irregular linear structures that you show in the most recent pics could be anything. It's possible they were caused by contact, either intentionally or accidentally, with an etching agent, or they might be irregular areas of oxidation. I strongly doubt this is a wootz blade, but to establish it is would require eliminating other more likely possibilities such as surface changes.
Regards, Ian