FANFICCERS' FRIEND - THE GREAT KEY (AN "OUTER LIMITS" CROSSOVER)

DOCTOR: 

What's the Great Key? 

ENGIN: 

It's an ebonite rod carried by the President
on ceremonial occasions. 

But it's actual function, if it ever had one,
is a complete mystery. 

"The Deadly Assassin"

Here is a definition of ebonite in Terran terms

A relatively inelastic rubber, made by vulcanization with a large amount of sulfur and used as an electrical insulating material.

'THE OUTER LIMITS'
"NIGHTMARE"

From the IMDb:
A stranded team of soldiers are captured and experimented on by demonic looking aliens.

Unified Earth is at war with the distant planet Ebon, a war which was prompted by an unprovoked attack by the Ebonites.

So the ebonite key could be a relic made of vulcanized rubber, but that doesn't sound like it was worthy as a totem of the Gallifreyan presidency.  And although I'm no scientist, I don't see how a rubber product could serve as a conductor for the energies transmitted by the Eye of Harmony.

However, I'd like to think that instead it was a gift from the Ebonites eons ago, perhaps in thanks to the Time Lords for their help in defense of Ebon.  (Which means the word "ebonite" in that quote from Co-ordinator Engin should be capitalized.)

It certainly would be an interesting theory for a sci-fi crossover and even a source of fanfic.  For instance:

As to what kind of help needed, perhaps the Ebonites had been attacked by the Krillitane.  Maybe that's how the Krillitane got their bat-like wings....

What say you?  
Just remember - if you write it up, send me a copy!