Transferring my world to a new world...help!

[ShadowJiraiya]

Hi. I'll get straight to the point.

I don't want to lose anything I've built, but I need to make a new world, as I created a world before I fixed the actual Voltz server files. I ran it with the minecraft.jar, not realising that doing this wouldn't allow me to utilize the mods within Voltz, as none of them worked. I fixed the server files today and all the mods are working, but I can't find any Voltz-related materials, i.e. Osmium or Copper.

 

Is there any way I can transfer the inventories of all players and whatever we've built to a new world, so that these materials will spawn?

 

Thanks a lot.