No, there is no Register-Level Programmer's Manual for the PCI-603xE series boards.
The one that is available out there is the one for PCI E Series. I think that the 602xE boards' conventions are the same for those of the 603xE boards.
The link to download that Manual is the following: http://digital.ni.com/manuals.nsf/websearch/5978CE4A83119E50862566FA0075F424?OpenDocument&node=132100_US
Hope this helps.
Aguila
