This has been discussed quite a while ago. The way the widgets are defined now does not allow to simply port the 0.4* version skins to the current release. To get there, someone has to put a lot of effort into setting up an entirely new skin with the style of the old one, which has in fact been done already. I won't hesitate to put the link here once more:
Daevaorn's classic skin. mikeloeven, if you like the theme of the stone GUI, why not try modding it yourself. It is probably not to difficult to get to something similar. Just ask around when you get stuck somewhere. And the inclusion of skins is straight forward, you simply have to put a zip file in your art/skins and select the corresponding new option from pslaunch.
May the light guide you.