Greek helmets galore

[PMBardunias]

The Gorgoneion is an old Apotropaion, a protection- and deterrence-symbol. In mythology, the cut-off head of the Gorgo Medusa was worn by Athena.
The horns surely have a similar meaning, the strength and power of animals (e. g. bulls) shall be transferred to the wearer of the helmet, who appears bigger and more ferocious.
The wheels are debatable. I suppose a connection to the underworld, because on a huge apulian-volutekrater they are shown hanging from the roof of the palace of Hades and Persephone.

Any idea on where/when they start to be added to helmets? Perhaps to impress the indigenes if the below is correct.

The question, if the helmets with these fragile decorations (cut out of thin bronze sheets) were used in battle, is fully legitimate. These helmets were undoubtedly made in greek workshops, but I think they were actually worn by indigenous people. Compare apulian vases: the main customers were indigenous aristocrats. An often used term is "ceremonial armour", but a use of this armour in unknown ceremonies is hypothetical. Maybe these helmets were made exclusively for the burial, analogous to the apulian vases which should probably show wealth at the burial.

That is interesting, some obvious battle damage would perhaps settle it. One thing I think that speaks against a use as soley grave goods is that they appear to be removable, fitting on little projections from the sides of the helm. Why be able to remove them if you are going to bury the helm and never wear it without them?

I assume you mean made by the Italian Greeks for peoples like Messapians and Lucanians, not made in mainland greece for the Italian greeks.