Air tank possibly dangerous?

I have an omega little "pony keg" air tank that has been awesome for years.
It has 1000 PSI inside and it is stuck. I can turn the valve. Neither will letting the purge open (I expected that of course but I was exploring how broken)

My first instinct was to twist the valve off and I put the tank between my leg and was about to twist and then I thought about what the hecking heck I was doing.
Can our awesome community please tell me how to NOT blow my balls off?

I just want my lil tank back it's really great.
 
That's the same gauge, just turned to a different position.

mike
Look again and think about component positioning on pictures. For making it easier I marked some of them and drew an arrow pointing to that gauge that shows ~3000psi.

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