You could create new shares and keep a buyback offer open, this is exploitable however:
Let's say you sell 2000 shares and 4 weeks later buy back 1877 of them @1.28. You then have an open buy order for 123 shares @1.28. Then, to get back to 2000 shares emitted, you issue 123 more share, totalling to 2123 shares, sell 2000 shares and most likely this buy order will be fulfilled quickly, but not by the sleepyheads that did forget to sell their shares in the first place.
If possible with GLBSE, you could ask them to destroy the shares after paying the final dividend, they might need a way to liquidate assets anyways. Perhaps a feature request for a "liquidate asset" button (paying a final dividend and destroying all shares or returning them all to the issuer) might be in order?
