Italic D: First or second century?

[Matthew Amt]

Avete!

Not to drag this too far off-topic, but is there actual visible evidence that certain helmets have been "cut down", i.e., had neckguards or other parts deliberately removed by the user? Are there chisel marks? Or could the neckguards simply be lost due to corrosion? I have no inherent objection to modifications, just curious about what has actually been found versus what is being theorized.

Thanks!

Matthew