get a con resigner that resigns console_id. done.
To update, I went ahead and attempted this and didn't have any success. Signing in locally isn't, and has never been, a problem, but, no matter what combination of resigning, rehashing, and comparing the console, profile, and/or device ID's I used, I could never get the older profile to connect to XBL. I checked and re-checked numerous times over, and injected all the data/ID's from the working profile over to the old one so they were a seemingly perfect match, but it was always a no go.
Perhaps I am completely overlooking something, and feel free to let me know if so, but, at this point, unless Gazza's theory ends up being correct (for the record, I don't have the KV for the new console, so that's the one thing I haven't attempted yet), this may just be a lost cause. Hopefully, someone can tell me otherwise.