Shortening sleeves is not a problem - any tailor can do that. Not sure a tailor could do anything about the waist tho. Jacket is just on the side of too small around lower waist area (hence does not fit your butt well), which is why that vent is flaring out. Usually if it were a belly problem, the jacket would flare out in front as well. You are probably OK around the shoulders and chest, but only just about (a slight strain on the top button - it should be comfortable, not trying to pull button out of fabric). If you want to stick to that kind of fit over a fuller body, I would suggest 42R but make sure the shoulders are around same - too wide a shoulders and you are in heaps of trouble - it would take a suit maker to make that alteration rather than a run o the mill tailor. I concur with other members, go for a fuller fitted suit and get tailor to make adjustments. Anyway, how comfortable does that jacket feel on? If you are feeling a slight pinch on underarms, it is usually an indication of jacket too small. Center vent is a deal breaker. Return. Depite the myth, there is nothing at all wrong with centre vented or ventless jackets. Dual vents are an elegant, but lazy way of helping a jacket to a better fit. If properly fitted, a centre vent or ventless jacket is fine on the right person.