How can I salvage macos resource forks when copying from a non hybrid ISO 9660 Rockridge CD
If the resource forks are available under the names you're describing, here's a way to recombine them:

cp -a /source/filename /destination/filename
dd if=/source/._filename of=/destination/filename/..namedfork/rsrc


This will still not copy over the type/creator and other Finder metadata, but it will copy over the resource fork.