The literature I have contains direct conflicts in a minor detail of a classic streamer recipe.
The conflict is specifically on the thread, or head, color for the Edson Tiger, Light and the Edson Tiger, Dark.
My sources are reputable texts themselves. 
Any help would be appreciated.
Ray,
I may have the same resource book as you, but here goes. From Streamer Fly Tying and Fishing by Joseph D. Bates
Edson Dark Tiger Bucktail
Head: Yellow
Tag: Three or four turns of narrow flat gold tinsel
Tail: The tips of two extremely small yellow neck hackles back to back
Body: Wound with fine yellow chenille
Throat: The tips of two extremely small red neck hackels (to simulate gills)
Wing: A small bunch of brown hair from a bucktail dyed yellow, extending just beyond the end of the hook. (An important element in dressing this fly, which is often overlooked, is that the wing must be short enough so that it will not in the bend of the hook when the wing becomes turned under the hook when the fly is fished)
Cheeks: Jungle cock, extremely short. (use eye only) ****As dressed by the originator)
Edson Light Tiger Bucktail
Head: Black (This fly is tied with black thread rather than with yellow thread because the black does not show when applying the peacock body. Many of Mr. Edson’s early versions were dressed with yellow lacquer over the black head, but this no longer is considered necessary)
Tag: Three or four turns of narrow flat gold tinsel
Tail: A section of barred wood duck or mandarin duck feather long enough to show two black bars
Body: Wound with peacock herl, several strands being twisted with the thread while theya re applied. The body is fairly full: the number of strands depending upon the size of the body.
Wing: Yellow bucktail dyed yellow, short enough so that it will not in the bend of the hook. The ends should be fairly even
Topping: The tips of two extremely small red neck hackels, not over 1/3rd as long as the wing. (a section of red duck wing feather was used in the early versions)
Cheeks: Jungle cock, extremely short. (use eye only. See notes under Edson Dark Tiger Bucktail on hooks and use of optional gold metal cheeks)
****As dressed by the originator)
I hope this helps.
Jim Smith
My copy of Bergman’s Trout (plate 11) shows a yellow head for the light and a black head for the dark. Just to confuse matters.
Here’s some more originals that I have. The Tiger Dark with the yarn body had cheeks/eyes, but just the stems were left. All of them have the same type of tail, and the ones with the JC cheeks are on loop eyed hooks.
