Getting a broken pin out of a B8 Valve Holder.

[boater sam]

Having tried a couple of suggestions, I find that the broken pin will not push through from the underside, so I can oly conclude that the tag end snapped off below the twisted part of the pin, and that it's stuck fast due to the twist.  Re-reading your suggestion, Sam, I'm just wondering what inserting a small screw at the tube end will achieve, but if I can find a small-enough screw I'll give it a try.  Of course if I can determine which, if any, if the unused pins are internally connected to the anode, I could simply rewire the anode connection to  the pin in question instead.

I thought if you got a grip with a thread in the socket you could use it to pull the contact out.
A silicon diode/s is certainly a solution, or as you suggest, de-base a rectifier valve and transfer the anode? to another pin but making a special, heaven help the next repairer!
But if you connect across under the base to another unused pin it would be obvious.