This is the first time I've used the glass substrate version of the LED filament. So it was somewhat disappointing when they arrived loose and all bent in random shapes just like the metal substrate ones, but scrunchier and deader! Out of the four filaments just one was still intact, and it happened to be the one that was passing through the machine that puts the phosphor loaded silicone on when it farted. As a result the silicone bead has been applied in a somewhat non-linear fashion. But it works, so hey.
That was just the start of my woes though. After a lucky polarity guess (there's a wee hole in the tab at the positive end) I soldered it in place and unknowingly, because of the thermal mass of the copper support it had pinged off it slightly before the solder had fully cooled. Just enough to work when I tested it, but not after I had permanently resined the tube into the base!
Note.... The only practical way to get the test tube back off the base is to wrap it in tape and smash it!
So it's now on properly and works fine. Strangely pink shade of white, but still very nice. Especially with a super-low power consumption of just 0.3W which would cost less than 50 pence/cents to run 24/7 for a full year.
The circuitry is just two quarter watt 47,000 ohm resistors in series with a bridge rectifier and the LED strip. (For 240V use.)