Herve,
Thank you for responding.
I understand about how myHack has it's own generic Extra files and that I need to download and use a bootpack from here when I build my USB boot device. Those steps were covered in the "Pre Installation" document (http://www.osxlatitude.com/edp/pre-installation/). And yes, I used myHack to create my USB thumb drive and then re-ran myHack telling it to use the Extra that I unzipped from the bootpack.
It is now that I have my question. The "Installation", not pre installation, document (http://www.osxlatitude.com/edp/installation/) says in step number 7 to run myHack now against not the USB drive bu the real laptop hard drive. Step number 8 says that myHack will ask if I want to use a generic Extra folder or if it should prompt me to use a specific one I have. Is the myHack "generic" Extra actually the Extra from the bootpack because it has been written to the USB drive or does myHack have an embedded generic that can override the one that shows in the root of the USB drive?
The documentation isn't clear. If the Pre-Installation steps were followed then Step 8 should have a decisive answer.