Just a guess, but this might be a last run FF605 before the rod was discontinued (reintroduced as Fenglas in the '90s).
They may have colored the resin to make it look like graphite in 1980.
How do the blank diameters compare? Also, how does the action compare?
The 6' graphite rods I can think of, aside from not working well except for tomato stakes, have less-than-pencil-thin butt sections.
Is this your photo or someone else's? Add enough blue color correction (or absorb red and green in shadow) and brown turns to black.
Automatic color correction under yellow lights can add up to give that excess blue with flash.