THE REPLACEMENT CDROM [DISK 3]
The replacement cdrom 3 is labeled Small business server 2003 Premium [but not to worry - it's the same bits needed for Standard]
It looks like this -- [click on picture to enlarge]
You can also tell that it's the new disk by looking at the back inside ring of the cdrom .
Your original CD will have X10-03482, x09-73382, or x10-03888 on the inside ring. The replacement cdrom has x10-30773 [trust me.... get a magnifying glass...it's there]
An easier way is to put the cdrom in the disk drive, click on explorer.... the SBS folder will be dated December 1, 2003