I think that the jacket can be let out in the waist and would fit near-perfectly. I'd take it to a good tailor to see what could be done. The shirt fits pretty good. If you're satisfied with pretty good - keep it. If you're not, then go bespoke or MTM.
Agree. Jacket can definitely be let out from the waist. Had the exact same problem with one of jackets. It was too tight at the waist and was tugging on the left vent, pulling it outwards. Letting the jacket out will resolve that.