Ah here's where I can chime in!! I already have this cosplay so yea..And it's mostly hand made. I bought a grey sweater off ebay that was an old navy brand and dyed it navy blue (it came out slightly navyblue/grey with looks pretty awesome actually. I cut the sleeves off first though, then after it was all dry I put a zipper in the center, cut the collar in half (it comes folded over, but you don't need that much length and you don't need it folding over, it stays up just fine) then I made a sleeve from a pattern I already had drafted. Remember to make it pretty big on the wrist area because that's how his is. It's smaller at the connection area to the shirt but bigger at the wrist.
Pants: Buy them at walmart or wherever (I got mine at fred meyer but that's just cuz I was there and they were on sale) and get cargo pants. The kind with the pocket on the side and NOTHING ELSE!! I can't stress that enough. The cargo workpants with the loop for a hammer are not what you want. Anyway, then draft a rectangle for the big pockets and sew them around the smaller ones that come on the pants (BAM!! hidden pocket!!) then make a smaller rectangle for the flap of the pocket. Do this on both sides. Then get the really thin belting stuff. it's usually near all the elastic and stuff on an oval shaped spool thing and you get it by the yard. Measure arounf the pants at the top ot the pocket and the botom like this:
See where the red is? Measure there, but all the way around. Notice the top doesn't go over the flap..this is how his are so that's what I did..Then after you have both measurements (top and bottom) double that so you have enough on the other side, each one also connects like a belt at the back of the pants. this means, at the top, you have to sew the 2 areas at the flap then belt them in the back..Then the bottom one just wraps around.
When you get the full measurement, remember there's also a lot hanging from the back where the buckle will be, so add about an extra 7" for each one (that means 28" added to your last total amount) then buy that amount plus a little extra just in case. Then just sew it on. Use little buckle (they don't make them that small at the fbric store so just buy ones that are close enough) and you will have to sew the hanging part to the like so:
Do that for all 4 areas.
If you want help on the halfskirt thing, I can do that too
That's my cosplay