I managed to open the SIM slot of the phone and inserted a working SIM from another phone. Since the SIM was not detected at all, I decided to give the nightly CynogenMod 12.1 on the phone. Again via SFTP to SSHDroid in the LAN.
An Optimus G E975 (Intl) was still waiting for wakeup, but official updates stuck at Android 4.4.2.
So I applied CyanogenMod to that phone and since it was not that easy to gather all the necessary information, I write down a short protocol of the steps, that helped in my case. I started with the rather incomplete (with respect to rooting and recovery) howto at wiki.cynogenmod.org.
I recently upgraded my iPhone 5 to an Optimus G, which fits better to the profile of a Linux User and after I was never satisfied with the results of Siri (at least in German), the voice recognition of Google Now is in comparison more than convincing.
It was time for another update from https://github.com/nadlabak/android/downloads.
It was just about time to update my Motorola Milestone to the latest CyanogenMod, providing Android 2.3.7.
Please find the final CM7 release at the usual location: https://github.com/nadlabak/android/downloads
Waiting for the upgrade to a newer post-2.1 Android by Motorola, I heard rumours about the Android 2.2 released recently, that were not very positive with respect to quality.
So I decided to get Android 2.3 via CyanogenMod on the Milestone with the help of OpenRecovery G.O.T..