spoofing a ms25 drive need some help

alright I've read through the threads about spoofing my 360 drive, and I have found a lot of helpful stuff on it, but I just had one question about it.

I have a broke hitachi 47 drive that I am planning on switching with a already flashed ms25 drive. Problem is, that from what I was reading, I would need to load the original firmware from my ms25 in toolbox. I had accidentally deleted my original firmware a while ago and only have the ixtreme on their now.

My question is, can I load my custom firmware in toolbox and still spoof it to the hitachi 47 drive, or will I need to get a new samsung or benq that has the original firmware?

thanks for the help.