Similar but opposite problem for me. Sorted by TM Lewin.
I’m a 32 waist and 40 jacket for the shoulders. But thanks to being a runner and a cyclist, I’ve built heavily built thighs, and a slim upper body. Can’t even get a 32 waist trouser up my legs. So they sorted out a 35in waist trouser, and a 40 jacket. Had their in-house tailor bring the waist in on the trousers, and taper the jacket for only 19 quid over the price of the suit.
Picked it up this morning and it’s a perfect fit.
Oh, and the best bit, because it’s their tailor who does the alterations, it’s all regarded as part of the suit, so any problems with stitching, fit, etc, they sort it.