I finally tracked down a name - Justin O'Shea - and a bunch of images to this gentleman that dresses up quite well with a biker meets rock 'n' roller look.
Flatstock will be making it's debut during the Primavera Sound 2012 festival in Barcelona, Spain, at the end of May. There will also be an accompanying art exhibit at the Virreina Centre da la Imatge. If you're there, do check it out and support these amazing artists.