I think you should probably believe what it was actually bought as, as only so much can be told by pictures. If it was labeled as a parrot white, than it's likely that you have a hybrid mut of random fish. I would be hesitant to breed something with a mixed lineage.
Nice fish. I could'nt tell you for sure about convicts but "Round" Green Terrors cost more and are more sought after than regular GT's. I'm thinking it's the same with "round" convicts although yours is the first I've seen. Just my two cent's.