i love talking about my dog.
here she is looking regal:
He could buy a L and selectively dunk the sleeves, collar and shoulder in a vat of boiling water....
I've done it w/ buzz ricksons sweaters and its worked reeeeeally well.
Well then the best and easiest solution, is to lift. That way his shoulder will fill in to the shirt and maybe he'll lose that beer gut along the way..