The gold ring is usually loose, and simply held by pressure from the Rhodium ring above it, which is pressed on at the factory. You may try simply pressing the cap a little to see if it will tighten up, but don't get too carried away, or you may crack your cap. If that don't work you may need to disassemble the cap, and put the center band assy on something solid, then use a press block the same size as the tube to tighten it up. If that don't work, the last resort is to use a press block to actually remove the gold and top rhodium band, or at least move it up about half way, then take and spread a very thin coat of med ca under them, and the repress them tight.
However if you have gone to the trouble of getting that far, you might consider simply removing the gold band, turning one from the leftover blank that would match, and installing it.
Of course if you've progressed that far down the slippery slope, you will need to knock out the gold finial and custom make one of those. Then there is turning a matching nib cover, and the list goes on and on
Enjoy!!
