Text and context

[Juan_Sali]

The script could be an attempt to craft a writing system for a previously oral-only language

I find it highly improbable. When an oral language starts to be written they use to take the written system of a near written language (by proximity, commerce, the language of their conquerons ...). There is no need to craft a whole system, it is easier to addapt a known system of reproducing sounds to the sounds of the oral language, it is a question of economy.