I just picked up this vintage Italian Panama Aerometric fountain pen but am unsure about how to get the metal cage off so that I can replace the sac. I think that the cage may be shellaced on and in that case i suppose heat would do the trick. However instead of rushing in I thought that I would ask here. Thanks Philip DSCN0887_result by Seville36, on Flickr DSCN0886_result by Seville36, on Flickr