If I come across any suitable metal, I'll let you know.

[Edward grows more solemn when he hears about Donatello's brother and his damaged shell. He's too polite to bring this up, but he used to catch turtles in the streams that ran through his family's estate, and he's aware of how much they rely on their shells. If there are turtles here with the intelligence of humans, and they need protection for their shells, that should be a high priority for the convoy.]

I take it you'd be capable of designing them, had you the right materials. Is there anything in particular I should be searching for?