Notch Lapel Crop Blazer

The chart says 12 is a 39 chest. Usually Designer brands run small this does. I’m a 38DD, that’s my band size of course. But I will be wearing this blazer, happily, open. It’s at least 3” open. However, my arms which are really long, the sleeves go slightly past my wrist. That never happens. I’m short waisted, so thankfully it’s longer on me than the Tall model. I’m still happy with it. It’s made very nicely, lined and a true white. Thus far everything was off white or not a blazer. There wasn’t a 14. Now I know JW runs small in the bust, although I fear the sleeves on a 14 would have needed altering?