Not quite. To my quick glance, I'd say indeed vaillantii. The dorsal is down, perhaps misleading Mat. My vaillantii looks like this one, chunky fella.Guess that answers that
The person I bought it from said it was 6”. But I measured it as well.8" answers your original question ! (Maybe start with that next time)
Nice pick up, but boy will this grow bigger than a Duopalatinus!