I'm back, and happy to have a go at your questions, Ian.
Thanks for pressing me; sometimes it helps me think; let's see if now is one of those times
I agree that "the progressions of weapons development" I suggest "may or may not be true" they're just feelings based on examples I've seen; no real folklore, even, and I'd really love to know better what's going on geoculturally.
I agree on the thru tangs as European; the tube-handle/socket more likely from mainland SE Asia. But joined to those European thru tang are blades of various degrees, of course, of native influence. The matulis seems particularly native, and I'll tell you why; first, the chisel grind which I see only on ones that seem solidly old; weren't you saying yours is c ground? Or just bringing up the idea? Am I confused? It's less common on them than a wedge shape, but is one thing that may suggest a Visayan relation. Now, the blade is much the same shape overall as an old, "garab" talibon, the kind with a curved cutting blade (the tip of the matulis), anled forward from a triangular shaft/ricassoe (sharpish, very wide, even guard-like, somewhat vestigial, and somewhat transitioned into a smooth s-curve on the matulis, but present), and, sometimes, on old ones, though not all old ones, the same overall wedge-section chisel ground only at the edge/secondary bevel. Look at Rick's recurved pointy one; I think it was the bottom one in the pic (?)
I think the natives had pointy daggers, at least, if not swords, on their own, and contact with the mainland would be as influential as Europe in this regard, no?
The tear-drop shaped shaped guards seen on some of these seem related to minimal Moro guards and lumand integral to the ferule/handle flat quards, and the crossguards I've seen on some of 'em seem as Lumady as they do Europy.
I agree about the pan-imperial trade, and by the way, you should see these two matulis-like Mexican daggers (bowies) I just got, and you know what else reminded me of these daggers, is that picture of the guy with the cape for a shield on the navaja thread; the blade is very like my two little Mexican bolos.
I think you have seen transitional forms, and just haven't recognized them as such; I think indeed, matulis is such a form. There are also Visayan swords with a talibon blade or a very talisbesque blade with the same cutting blade and forward lean, but no ricassoe, often with guards, and occasionally wedge-sectioned. There are smoothly s-curved talibons, but especially talibesques with octagon ferules. There are binagons (or tenegres?) with triangular based forward leaned talibesque blades, many of full regular sword size, and with handguards that may relate in here somewhere......One sees so many different handles on talibons and talibesques, and so many blade varieties; slim tip or wide chisel ground or wedge overall wedge overall flat or overall thicker to the cutting edge (like my Mexican daggers, too!), curved or straight cutting blade, various angles of ricassoe and of tang and edge in relation to hilt; a wild profusion.
Very sorry, but pics are not my best capability at all;I've almost filled a roll & the rest are assigned and my books are minimal, etc.....
I have not seen a full tang sword or knife with a chisel grind that was of native manufacture and intended for local use.
I'm also not sure what you mean by the C-grind knives referred to below.
I don't understand this part of the question, perhaps I've answered it anyway, by rambling? Or maybe you can reword it for me?