"If I understand Koehl's position, the Sea Peoples moved eastward through southern Anatolia. They conquered and settled the Amuq valley ("northern Philistia"). Their migration toward Egypt came later. The Amuq valley is a good place to look for the evidence Jon asks for. CW"

Clark.
You have now moved the exchange towards debating the origin of the Peleset/Philistines. Tell Tayinat was not destroyed at the end of the LBII.
Aegeanized Asiatics indeed did reside in northern Syria, eastern Cyprus and southern Anatolia.

You wish to look for the immediate point of origin for the Peleset then yes, Tell Tayinat is the best argument to date.
For the Denyen, Ia'Danuna (Isle of the Denyen = Cyprus), and perhaps Adana.
For the Tursha = Tarsus, for the Weshesh = Issus, for the Ekwesh = Ahhiyawa/Ahhiya/Que, for the Shekelesh/Sikalayu = Syria, south of Ugarit.
East Cyprus, classical "Cilicia" (Hilakku), coastal Syria.

The issue I was interested in was by what means are we to determine an Aegean conquest of; Abu Hawam, Tell Keisan, Ashdod, Ashkelon, Dor, Aphek, Beth Shemesh, etc. and all the numerous Levantine sites which demonstrate a LBII destruction level yet bare no subsequent evidence of which peoples, foreign or otherwise, caused that destruction.

Medinet-Habu, read in its entirety not selectively, provides a story where we see Ramesses III advancing north in Syrian Hittite territory, notably taking "Tunip of Hatti" and the island city of Arvad (Yereth).

The Hittite alliance (Hatti, Kode, Carchemish, Arvad, Alishaya) were assisted by northern coastal tribes of Denyen, Shekelesh, Tursha, Peleset, Sherden, etc. who advanced southward primarily by sea while the Hittites advanced over land.

There is no reason to reach back to any hypothetical Aegean-based alliance of marauding 'Greeks' looking for a new homeland.
The Asiatic wars of Ramesses III (and to a lesser extent, Merneptah), had to deal with restless northern peoples and an equally desperate Hittite society who were suffering with starvation & internal political strife, which eventually tore the Hittite realm apart.

The "Aegean Invasion" hypothesis evolved as a result of speculations by DeRouge, Maspero & Chabas and even though being soundly shreaded by modern archaeology still sadly forms the skeleton framework of some modern conjecture.

Regards, Jon S.