Gas cap restoration, help!

[NCAmother]

Hi everyone.  I’m restoring an old 850T gas tank.   It’s starting to look better, but still looks like 💩. I’m at the gas cap restoring phase,  I am having a hard time removing the center screw.  It just spins and spins and doesn’t come out.  Stripped threads?  How would you approach this situation?

[Antietam Classic Cycle]

There's a nut on the inside. You will need to push down on the whole center section and rotate it to remove it.

[NCAmother]

There's a nut on the inside. You will need to push down on the whole center section and rotate it to remove it.

I’ll check it out tomorrow!  Thanks

[Matt Story]

I think these are available either new or aftermarket look a likes.  In chrome or stainless.  I think the same style was used on some Ducatis, so pretty common