the problem with the flying cap and goggles is what exactly the extra leather face protection is connected to, is it a flange of sorts to the goggles or is the aviator cap covering alot of the face too? maybe see if there is any artwork showing details of that.
retailoring old clothes is alot faster than sewing from scratch. that vest looks pretty good, I would use it as is really, the added items will make the costume.
this is concept art of him, with a pretty good view of the mask from the front and side. it looks like in reality the mask pulls over his whole face with just a slot for the eyes. its almost half ski mask half aviator hat i'd call it. I think if i can get a regular cap and some goggles it shouldnt be that hard to create something similar without modifying the two.
it also makes me wonder how on earth does this man not snap in half in a stiff breeze! look at that waist!