Technical Fuel cap seized

[Xylaquin]

My '93 cinq has been sitting unused for just over half a year, and in a bid to move it to a different location I went to put some fresh fuel in.
The key would only turn about 30-40 degrees, so I assumed the spring mechanism/plastic tabs further into filler neck had bedded in a bit.
With a bit of persistence I managed to turn the key further and the cap started to come off but then... snap

any suggestions on what to do now?
The barrel turns freely, but the cap is stuck, suggesting that not only has my key snapped but something in the mechanism has too.
I'm pre-immobiliser and have my original key, so can just make another copy. It's more so how to get the cap off that I need advice with!

 

[Mike1alike]

First thing try spraying some oil on its thread with a piped spray. Then... with force. Grab it somehow with a tool and twist it.

 

[Xylaquin]

What thread?
The cap is still in the body/filler neck, and the key turns loosely.

 

[Mike1alike]

You are right actually. Because cap seals it. Nothing would get in.
So... force it is then.

 

[Xylaquin]

Hmm, I can probably get the rest of the key out with superglue on the end of a flat screwdriver. But after that, I'm guessing take another flat screwdriver and jam it in and spin? Or pry and hope for the best?

 

[Mike1alike]

I would think pry and hope for the best.