O.O.
My husband has very broad shoulders and a small waist.
So, a 52-54 jacket looked ridiculous on the waist. And getting the pants to a 34 is crazy....
At O. place, they were able to change the jacket from a single breasted style to a double breasted style. That took care of the many inches too much in the waist.
The men's stores themselves seem like lately don't like to get into altering jackets--sleeves only, and hem pants.
Usually you do need a good tailor to do that.
My husband just spent a lot of money on a beautiful suit from Jos. Banks. Other than sleeves & hems they wouldn't touch the alterations! Really? That men's service in the retail stores is gone.
Tailor!
(When you google this, lots of UK sites pop up...)