more iiif print fixes

app/jobs/iiif_print/child_works_from_pdf_job_decorator.rb

@@ -38,7 +38,8 @@ def perform(id, pdf_paths, user, admin_set_id, *)
       # However, there seem to be cases where we still don't have the file when we get here, so to be sure, we
       # re-do the same command that was previously used to prepare the file path. If the file is already here, it
       # simply returns the path, but if not it will copy the file there, giving us one more chance to have what we need.
-      pdf_paths = [Hyrax::WorkingDirectory.find_or_retrieve(pdf_file_set.original_file.id, pdf_file_set.id, pdf_paths.first)] if pdf_file_set
+      redownload = pdf_file_set && pdf_file_set.is_a?(ActiveFedora::Base)
+      pdf_paths = [Hyrax::WorkingDirectory.find_or_retrieve(pdf_file_set.original_file.id, pdf_file_set.id, pdf_paths.first)] if redownload
       # handle each input pdf (when input is a file set, we will only have one).
       pdf_paths.each do |original_pdf_path|
         split_pdf(original_pdf_path, user, child_model, pdf_file_set)