Of course he is Deidara! We made Akatsuki outfits for Sasori and Deidara as our second costumes in 2007. In 2010 I updated the undergarments and we had a small photoshoot. Then we have all the videos we made dressed as the characters on our Youtube account.
After the first costumes back in 2007, I considered making the flashback version of Deidara. The idea got pushed back, probably because it would’ve been solo cosplay as Sasori’s "camouflage form" was not on our to-do list. But now since I’m going to attend Cosvision without Yoki, I remembered young Deidara. A week later, here is what I’ve got!
I wanted to cast new mouths for Deidara's hands and got rather satisfying results considering it was my first time making a partial facecast on myself. I thought that making a mouth in resting position would be easier and faster for a first timer. Also I wouldn't need to make positive cast from the mouth and sculpt a whole different expression for the latex cast given the time I have before the convention. At Cosvision I'm going to wear only one mouth, because I need one fully functioning hand without a lump of latex glued on the palm.
The only things left are to construct the sandals, add some finishing stitches on the clothes and try out the make-up. I also thought about sculpting the first clay sculpture Deidara presents to the Akatsuki who came to claim him aka. the fat spider.