"Rising Trout" says Harvey tied it with pale-green-dyed deer hair, which is then clipped. (The book notes that Ray Bergman tied his using cork.) These patterns are floaters, not underwater flies like today's Green Weenie.
In Harvey's memoir collected by Dan Shields, "George Harvey: Memories, Tactics, and Patterns," on p.22 a Green Inchworm is described as being tied from green or chartreuse deer hair, closed cell foam, or lacquered green cork. This is a dry fly. On p. 24, he describes a Green Weenie which he notes that he first tied back in 1934 or 35. For this he used green chenille but that he says he "now ties from fluorescent chartreuse chenille." This is his underwater version.
As an afterthought: Both of these books are wonderful looks back at earlier times in PA -- they are fly-fishing books that you might want to add to your fly-fishing libraries.