[Help] Recently bought a fat ps3 with cfw installed

Hello everyone.

I recently bought a CFW ps3 fat i don't know the series.
If i open system information in ps3 xmb menu. it shows me that the system software is Version 4.82
there's an mmCM below the Game menu in XMB which i can access and when i open system information in mmCM, it shows me:
mmCM version: 04.80.00
PS3 system: firmware 4.75 [SC-35 | PL3]
Firmware Mode: COBRA 7.54 compatible

My question is, how do i know which CFW installed? and I want to change/update to the latest CFW Rebug,...

[Help] Recently bought a fat ps3 with cfw installed