I would assume there are multiple versions of the xonline library in an .xbe near you. I guess you would need enough source to come up with a compatible replacement for every popular Live game, or the means to disassemble, patch and reassemble each xonline library. Once finished, I think a Live .xbe patcher is a sufficient solution. Good Luck! I've enjoyed the read.
I think there could be a way to extract all the data we need using a custom application. Instead of using the pre-compiled lib's, it may be possible to include the library source directly into the application and then it will be a trivial task to create a custom program to display all data used by the key generation routines on the screen. I've also just realized that this is not the xbox live thread *facepalm*
I'm starting to upload the "untouched" Barnabas source to mega and I will get my actual working build environment uploaded soon too