I have this frame, measured teh top tube diameter and it is a clear 15mm difference in diameter from the tube nearest the seat to the tube nearest the stem - i.e. it gets bigger towards the front on both the top tube and the downtube.
it has the flared seat tube but it has a tube for the brake bridge instead of a flat piece of metal - on the brake bridge there seems to be welded a washer so it acts as a flat piece of metal, this is in chrome and doesn't look to have been added afterwards.