Tshirt alignment is just knowing your spacial relations on the shirt and being able to adequately make it similar placement every time .... no defined one way ... find what works best for you, use seams or collars for guides, try to center from the sides, etc. some platens i've had to make custom just to ensure I get adequate placement on odd areas like sleeves or bottom of shirt seams. Should be the same process if your screenprinting, heat pressing or direct to garment printing.
Amazing sizing pdf find.
As for that artwork you're looking for ... do you have the rights to reproduce it? contact browning.