Hi Dan.  Good to hear from you.  
 
That's a pretty cool sword.  I'm always extremely skeptical of "excavated" swords.  Both Mark and I have a number of heavily corroded swords, all of them suspiciously similar. 
Your example, however, seems different, and your description of the others is very exciting.  I have one example with a lotus bulb pommel and petal/leaf detailing at the ferrule nearly identical to yours.  These features seem Thai to me, Ayutthaya period.  
Let's see what the others have to say.