I think your ID looks to be right. The fish looks more of a Brachyplatystoma now and is doing the tripod stand so characteristic of the brachies.
Cool! That's a first for me. I think this is the very first time for me when it can be said with some certainty this is a B. vaillantii. There are ~4 more fish that look like yours that have been reported and asked to be ID'ed on MFK and PCF.