Last psfreedom version (0.6) from extra devel already have JIG (downgrade) option. You can use it with PS3UPDAT.PUP and Lv2diag.self files from psx-scene. But fresh message from scene say's "I have 100% confirmed downgrading your PS3 console, kills Blu-Ray Playback!".
May be waiting few days would be wise decision.

p.s. sorry for bad english