Yes, that's a Tocantins, and looks to be a great one. Very nice colour extension into it's fins. Tocantins will develop the Panaque armbrusteri type of small and wide teeth layout like Xingu and Tapajos, whereas Araguaia have the larger narrow teeth layout like Panaque nigrolineatus. The Tocantins and Araguaia rivers run roughly parallel for their course and join near the city of Maraba. Your fish looks similar to other Tocantins that have appeared recently and were said to be from around the city of Palmas.
Teles Pires is one of the rivers found in the Tapajos basin and is where several of the specimens used for the description of Panaque armbrusteri were collected from. I think there are a couple different varieties within the Tapajos basin as juveniles can vary dramatically but the trouble is that very few adults appear, so judging what might be what is very difficult. This 'famous' fish is from the Teles Pires, and matches very closely one of the pictures used in the description of Panaque armbrusteri, so this is what 'true' Panaque armbrusteri probably looks like.
