Small business server 4.5

Two parter:
1. Is there a way to move the licenses from one server to another as we upgrade physical server boxes? The original license disk is missing, but would not be of use anyway because it is configured to the original server
2. Has anyone attempted an upgrade from SBS 4.5 to windows 2000 server? And if so how did it go and do you have any recommendations?
I am willing to give the points on both parts (150 each)
Thanks for your help