Hi I know im boaring with questions about creative BUT when you copy your "old/new" plot how to copy the items on it ?????? ???????
If you have access to worldedit, you can download the worldedit mod and install it. If you know the commands, you can copy your builds from your single player world and copy-paste it into your creative plot in the server. If this is what you mean, your welcome!
World edit is for donors check the shop when I did I went all the way to the Titan section xD and it said that you have access to world edit
Try downloading the world edit mod and watcch a youtube video on the commands then just transfer it will be quite hard but try, also try to (i know it would take ages and its boring) just rebuild it bro.
Everything is possible with world edit, you will need to be donator above to copy or get access to the world edit