I just saw this movie this weekend, and really loved the costume, so I've decided to make it for halloween-ish. This is the first time I've ever done anything like this but I think it's going to be lots of fun. As for the arm, I'm thinking of making a foam base, still need to decide what type of foam and how to make it, and then coat it with some sort of sliver material, like Edge's. I was browsing around and I came across this: Free Shipping! 8" x 60" Car Auto Vehicle Silver Mirror Chrome Foil Gloss Wrap Vinyl Film Sheet Silver Chrome Wrapping Vinyl Film-in Stickers from Automobiles & Motorcycles on Aliexpress.com, which I was thinking might work. I'm going to order some and do some experimenting, so we'll see.