Hey Ken - good luck with the auction! I'm thinking this fish is a cobra after viewing your photos and comparing to ours. Tapajos I - have a gold ring around the tail spot, Tapajos II (Cobra) do not! Also, the head shape seems more like a cobra - a little blunter.
A very nice fish - healthy & chunky, am surprised the fins aren't more torn up ~ being wild-caught. Someone should be very happy with your big girl, I don't know anyone with a female 14"+ ...