Confused what my phone model is
I just bought a used Sony Xperia but I am not sure what the phone model is. It is locked to Bell and the model number on the bottom of the phone says C6616 but when I go into the Settings > About, it states that it's a C6603 running on 4.4.2. Does this mean that this phone is originally a C6616 but flashed with a C6603 rom?
Also, I want to use this on Wind Mobile (AWS 1700/2100 network). If I unlock this phone on its current firmware, will it detect the network?