Hi Stan,
Thanks a lot for looking. I also found in litterature that GE used probed electrodes although the difference with Sylvania is that GE's probes are made metal foils instead of wires. Interestingly, GE's design has the advantage of incidentally providing electrode shields like those found in Philips fluorescent tubes, which decreases the electrode fall voltage and limit the end-blackening throughout the lamp's life.
Max