I don't know of a repository for this version, but it is still possible to download an ISO.
The name of the ISO is SLES-10-SP4-DVD-i386-GM-DVD1.iso
for the i386 version, or SLES-10-SP4-DVD-x86_64-GM-DVD1.iso
for the x86_64 version.
Here are a couple of download links that I found using Google :