Pergamon relief

[Decebalus]

The East-Celtic helmet depicted on one of the reliefs looks very like real ones found in East-Celtic graves, so we can assume that the other depicted weapons and armours have been modelled with the same accuracy on actual trophies.
I agree that Hellenistic forces would have made use of Celtic or Celtic-style weapons and armour (and the Celts of Hellenistic) but the origin of some of the depicted items like the mentioned helmet-type, the flat oval thureos-shield, the mail-shirt is clearly Celtic/Galatian.
The only sword-hilt I found which looks like Celtic La-Tène-style is the one on this relief.

Greets,

Decebalus/Andreas Gagelmann