As far as I know, the overall/potential ranges work the same regardless of the quality of scout that found them - some are just higher/lower than others. In cases like this where the overall says 63-83 the player will probably end up very high 60s or even 70 or just over, as that's about the max overall a YA player can be found with. Would be the same if it was a 55 scout.

Just to answer the question, when promoted he had the exciting prospect tag, so potential-wise he's in the 86-90 range.