Well, I submitted a support ticket about this, and the response is less than satisfactory:
QUESTION: “How do I know which license type (personal or professional) I own for each of my assets?”
ANSWER: “Unfortunately Fab does not have an intuitive way for users to check which license they purchased at this time. Though we here at Fab Support can check and let you know which license you have if you let us know which listing you want us to check for you.”