Okay, so some good news, and bad news.
I think, unfortunately, I won't be able to reliably add the groove into the aluminum. As they aren't forged or hammered, the aluminum, while a high quality alloy, is still soft compared to steel. I broke two blades getting the groove in, by either going through the aluminum, or because removing the material creates too much stress at the guard, causing it to bend.
However, I can still add the edge, and highly polish the blade. The screen used blade looks very shiny. This was a quick pass with an old polishing wheel, so I think with a new one, they'll get very reflective.