I saw togo with canvas lining in H Hawaii last month. Half the weight of Fjord and buttery soft. I compared the two (togo birkin, fjord hac) in 50 cm, so I don't know about 40s but the fjord was really stiff sided and hard to open.
PS The Birkin doesn't live in Hawaii anymore Mahalo
PS The Birkin doesn't live in Hawaii anymore Mahalo