I'd work on the assumption the measurements are correct. Japanse sizing isn't any more consistent than UK/US sizing. I'm a 43" chest so typically a generous US Large but normally a UK XL and had to go for a Japanese XXXL in a Beams jacket.
Yes that's French Moleskin - same fabric Hervier and Le Labourer use. It's a densely woven cotton. English Moleskin is sheared to give the fluffy texture, but French (and German) moleskin is left unsheared.