So I bought the sample run size 31 Walts from the epauletnewyork site (my first foray into wool walts and I am impressed). The waist is pretty good (maybe just a hair tight) but the seat area gives me a murphy in the back. Will letting out the waist a bit help? Do I let out the seat? Both?
I'd take it by a decent tailor in your area and show them how it fits you. Most likely a mixture of letting it out in the waist and the seat will work, but let them be the judge.