Celtic helmet of an Entrmont sculpture - Help

[S. Marcer]

Hello everyone!
It's a couple of months that I try to find more information about the type of helmet represented in this sculpted head from Entremont, a Gaulish oppidum near Aix-en-Provence in southern Gaul (conquered by the Romans in 123 BC and abandoned at the beginning of the 1st century BC).

In the most recent literature (M. Py 2011; M. Feugère 2011), the helmet is interpreted as a metal helmet comparable to a late variant of the western Celtic helmets.

The helmet have no apex, a round shape and a small and concave neck guard attached to the cap.

The only reference to a real helmet - that I was able to find - is an iron helmet from the excavations of Toulouse, Estarac dated at the beginning of the 1st century BC. (image attached below)

I wonder if any of you know or can point me other examples that can be related (for chronology and shape) to the one of the Entremont’s head? Maybe something from the Iberian peninsula??

Thanks for any suggestions!
Best!
S.M.

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