1. Do original DUALSHOCK 4 (CUH - ZCT2) series controller's serial numbers start with a special number? For example the DUALSHOCK first version starts with 1 and second version starts with 2. One of the serial number starts with 3911 and the other with 1911. Will I be able to check anywhere whether the serial numbers belong to original series or not?

2. Without opening both my controllers, everything matches with the original ones as per your findings above. However the L3 and R3 buttons function on their own and doesn't let me control the player and camera angle fully. The controllers have never been dropped or any physical damage caused.