Write entire/os questions

I have a 12200411 PCM - 02 camaro with a 3 bar OS and I need to revert back to the original OS, problem is I lost my original file when my laptop crashed a few months back. I do have a couple licensed stock OS pcm's from a 00 camaro. Can I do a write entire on the 02 camaro pcm with the 00 camaro data? or do we have another way to get the original OS for the 02 camaro back without having to have it reflashed with a TECH2 at a dealer? I appreciate the help on how to get around this problem.

That would be the only way other than a tech2/mongoose.