I'm looking specifically for info before the word 'Celt' came into use.
The oldest alternative to Κελτική (Keltikè) found in Greek texts or litterary fragments appears to be the land inhabited by Λίγυες (Ligues, often translated as Ligyans, Ligurians or Ligures), sometimes rended as Λιγυστικῆ (Ligustikè) as with Strabo (Geography IV,1).
It's unknown how ancient the name was, but depending the acceptance of a fragment of Hesiod as genuine^(1), it could go as far as the VIIIth century BCE. This descriptions of Ligues as a "peripheral" people inhabiting one of the corners of the world is reminiscent of the geographic role attributed later to Celts i by, for exemple, Herodotus : it could be further hinted at by their names, possibly coming from Greek meaning "noisy, loudmouth, squealers" (and, thus, close to the term and meaning of "Barbarian") or a comparison with the sound of lyras and sirens, with a potentially semi-mythical attribution. As such, Ligues would be initially for Greeks the set of Barbarian peoples that lived in the westernmost portion of the world.
From the VIth and Vth centuries BCE, several texts provide with a more geographical definition of Ligues and Ligustikè : the fragments of Hecateus of Milet's Periegesis^(2), the pseudo-Scylax's Periple^(3), the Pseudo-Scymnos^(3), Herodotos^(4),...
Overall, these authors first defined Ligures as inhabiting the land between Iberians and a city near Alps (Massalia, Antibes, Pise, etc.) even up to Etrusceans. This definition was made even more vague with a progressive iberization of peoples along the coast up to the Hérault river since the VIIth century and the existence of a mixed Ligurian/Iberian population (notably in the region associated with Elisukoi i.e. the region of Narbonne and Béziers) that Herodotus distinguishes both from Ligurians and Iberians (History VII, 65) hinting that this definition might not have been clear for Greek themselves, especially as the distinction between Ligustikè and Keltikè certainly wasn't to begin with.
Indeed, most of these definitions and locations of Ligurians were relative to the perception of Greek authors and settlements along the coast and their categorization in this worldview : but archeologically, local archeological cultures had more or less strong links with their hinterland and while the Mediterranean influences gradually became stronger during the First and Second Iron Age (Etruscean and Greek between Agde and Massalia, Phoenico-Iberian west of the Hérault river^(5)) the Halstattian and LaTenian influences on the region don't mark a radical rupture with previous archeological ensemble.
While the mention of Keltoligues (or Celto-Ligurians) by the IIIth century BCE onwards^(6) was formerly often postulated as representing a Celtic takeover of the region (which is unnatested archeologically), it's more considered by now as a specific characterisation of peoples belonging both to the Celtic ensemble (itself characterized by a certain sophistication of inter-regional exchanges, possibly born in relation to Greek presence) and to the Ligustikè thus be best understood as the maritime region where Greeks interacted with locals by trade, in what Dominique Garcia defines as a "territorial imbrication" : opposing both would be thus, even chronologically, a misinterpretation and misunderstanding of the terms, which nevertheless caused in the XIXth and XXth centuries a whole quest for an unreachable "Ligurian" people.
Rather than "pre-Celts", we'd be looking a a set of peoples defined by their relations and partnership with Greeks and the perception the latter had of a broad maritime area connected with their hinterland (probably importantly Celtic-speaking in Gaul and possibly Cisalpine Italy; quite possibly Italic-speaking in Italy itself and Iberian-speaking beyond the Hérault river, etc. and, why not?, pre-IE linguistic leftovers^(7))
EDIT : This is not to say that there weren't differences between the southern shores of Keltikè and its hinterland.
The region was part of a broader ensemble with an earlier and more widespread proto-agglomeration (altough these are called oppida, they appeared from the VIth century BCE onwards, in different materials such as frequent use of stone, and with an entiere use of intra-muros space) even if similarities with early proto-agglomerations north of the Mediterranean arc such as Avaricum or Heuneburg can be highlighted. (Altough they were quite different from IInd and Ist centuries oppida).
Fortified sites as Pech-Maho (possibly then known as Σαιγάνθη-Saiganthè), Ensérune, Montlaurès (the ancient Naro/Narbo), Lattara (both the original oppidum found in 2010-2016 and its more famous emporion), Le Cailar or Saint-Blaise among others represented a first social, economic and political sophistication in Gaul. This precisely because they were in an area of contact with Greek that dynamised indigenous devellopments (altough didn't caused them directly, except in relation with Massalia immediate neighbourhood) along the coastal trade ways (either by sea, or by the constitution of the "Heraclean Way", protohistoric predecessor of the Via Domitia)
^(1) Geography, VII, 3, 7; Strabo
Aethiopians, Ligyians and Scythes that milk mares
^(2) Ethnics; Stephen of Byzantium (fragments 61 and 62)
Elisyces : Ethnos of Ligurians; Massalia: Polis of the Ligustikè, downwards Keltikè, colony of the Phocaeans.
^(3)
3. Ligurians and Iberian. After the Iberians, there are the Ligurians and Ibe-rians, mixed up to the Rhodenus. Navigation along the Ligurians zone, fromEmporion to the Rhône, took two days and a night.
4. Ligurians. Beyond the Rhone followed the Ligurians until Antion. In this area, we find theGreek city of Massalia with its harbour
^(4) History V,9; Herodotus
However that may be, the Ligurians who dwell in the region inland above Massalia call traders sigynnai*, and the men of Cyprus give the same name to spears.*
^(5) The foundation of Agathè/Adge, a phocean colony, is strongly suspected having played a role into marking the geographical limit of Iberization in Gaul.
^(6) Geography, IV, 6, 3; Strabo
The ancient Greeks gave to the Salyes the name of Ligues, and to the country which was in the possession of the Massaliotes, that of Ligustikè. The later Greeks named them Kelto-Ligues, and assigned to them the whole of the plains extending as far as Luerion and the Rhone
^(7) Altough identifying radicals classically associated with a "Ligurian substrate" to a particular language is difficult at best, particularily because it's probable we're talking of not necessarily related peoples : -osco/-asco/-uscu or -elu can be found on both sides of the Alps without much further details, and there's a tendency to call "ligurian" roots or etymologies seemingly unrelated to Celtic, Italic or Greek (or even some that can, as -brica, supposedly different in some old sources from -briga)