Helmet textures are inconsistent

The Bug

The textures of equipped iron helmets, gold helmets and diamond helmets are incosistent with their item counterparts.

The mentioned helmets, when equipped, have a nose part that is not shown in the actual item, while the netherite helmet's item texture has this nose part visible. View my attached image for a visual representation.

NOTE: This issue does not apply to the leather cap, chainmail helmet, or turtle shell, as these items do not have a nose part when equipped, and are thus not incosistent with their item textures.

Reproduce

• Get an iron, gold or diamond helmet

• Equip it

• Compare the item model to the model on your head

Observed Result

The nose piece was missing

Expected Result

The nose piece wouldn't be missing