This may be a stab in the dark, but I know theres a bunch of people on SF who are really into fitness.
I just purchased the type 3s jacket in XL which has measurements of : Chest (44 inches), Shoulders (18.5 inches), Sleeves (24.5 inches).
My measurements: Chest (about 40 inches), Shoulders (about 18 inches, maybe a tad more), arm length (?)
I actually really like the fit of the XL jacket on me now with just a t-shirt.
The XXL has measurements of Chest: 46 in,...