Ummm no not sure where you would get that. The slim PS3's have SOME of the firmware files on the HDD but all the important stuff is on the NOR flash located on the PS3 motherboard. If you update higher than 3.55 there is no way back to CFW or jailbreaking at the time being. I suggest dump the dongle go to CFW 3.55 Kmeaw or Waninkoko v2 (v1 bricks phat PS3's so avoid, slims are fine).
If you update past that then try a new HDD it will prompt you to reinstall the current firmware that is on the NOR flash even if it is only a portion. Besides once you go past 3.55 Sony locks the HDD to the console and you can't just pull out the old HDD and add a new one. They are getting sued for this as it was another feature removed just like OtherOS they have removed the ability for the home user to upgrade your HDD so if you buy a new one get one that is large enough.