Interesting thread...
I see where you may mistake these swords as being Visayan. These examples may be parang naburs, but then again I'm not to familiar with those swords. And Batangas and Bicol has been brought up as a possible origin. In the past I have made references to the "bathead Batangas bolo." I've also posted a year ago when I was in Batangas that those swords are possibly from Bicol instead.
http://www.vikingsword.com/vb/showthread.php?t=2818
http://www.vikingsword.com/vb/showthread.php?t=594
So here's some food for thought. The first sword is from Bicol. This sword was given to me by my Uncle several years ago and I always thought it was from Batangas. Last year when I was in Batangas, my cousin told me that it was originally from Bicol. The most prevalent figural hilt form in Batangas is the horse, but the bathead form can be found there as well. Most scabbards in Batangas are made of tooled leather. The scabbard on this example is wood with a flared toe...similar to certain Visayan scabbards. The other two swords are very similar, but with different blade styles. They are also from the Philippines most likely from Bicol. One now belongs to Ibeam. All three have bathead hilt and similar scabbards. The blades on the swords in question do not look like any of these examples. Study the differences and make comparisons....maybe you'll find your answers.