Solid stock SS1 variant or FN FNC?
First batch/early production SS1 (probably some early SS1-V3 too) still uses FNC horizontal handguard before switching to the vertical ones.SS 1 V3 Pindad. FN FNC handguard is have horizontal serrations. All SS1 version using vertical serration to differentiate it with FN FNC
The one on the video were the SS1-V3 due to it's polymer stock, vertical serration handguard and the absent of gas cut-off for rifle grenades as they are removed on SS1 series production. SS1-V3 were produce in limited number early on, mostly went to training/non frontline troops and also for Paspampres honor guards with special chrome-plating applied.
FN FNC only available with FN skeleton stock, they also got the gas cut-off flap for rifle grenade.