The middle bow may be an all Walnut bow? Other than that I can't be sure what else I answered wrong, so I will look forward to hearing the correst answers.
When I say "Walnut", I am actually not sure what species I am referring too, but I am certain it is not Black Walnut. I think they called it Tropical Walnut, and used it on the 59/60 Polar, the 61 Walnut/PH Kodiak, and a slew of other bows.