lt - I think you may be right and me in error. The Purdey and Woodward snap underlever hammerless guns do use the Daw cocking lever, but, come to think of it, I don't have a hammerless sample of the thumb lever pattern (I remember seeing one, but I don't have information at the moment so I may be wronmg). I suppose it may have been used only for bolting on hammer guns.

Good catch!!