It's difficult just because it seems to be a new focus that's still not perfected. I have the best classification system (that works for my collection) the scutes on the head in each country have there own unique patterns and sizes. Shell shape sometimes differs. I'm at my facility now about to give some baths and take some photos. Stay tuned. ( keep in mind I don't have Internet acces here so gonna have to wait till I return to my house to post them)