[DesertRhino]

“Wouldn’t they have known it was a comb without having to write “comb” on it?”

That was in case some occupants of the British Isles ever found it.

[Defiant]

Or maybe it was the name of the inventor, Dieter Kama. He put his name on it, like Kleenex puts its name on the box. His invention became so popular among the previously unkempt Germanic tribes that they even started calling it the Kama, and that word has come down to us as "comb".

That makes sense now.