Notice to my future self: If you want to see a list of files that are referenced by a Debian dsc-file, you need to use:
dcmd dsc-file
The output is the list of files in its ‘Files’ section, plus the dsc-file itself. You can also apply dcmd to changes-files. You can also use a command as the second parameter and do funny stuff with all those files within the dsc-file.