time machine restore to external disk issues

[Polgs]

I have a time machine backup of the mac internal drive and an external HDD. The external drive had an invalid APFS object map error so I had to reformat it and now I'm having difficulty restoring its contents from the backup. I tried using the Time Machine app but when the process found a single file on the backup that it couldn't read, even if it was just .DS_Store, it simply displayed an error and stopped - not very helpful. I then tried the same from terminal using tmutil command but it failed the same way. I'm now using cp to do the restore but I'm not sure which options to choose. I tried with one folder using 'cp -npR' and the copy finished and told me that some directories failed setattrlist with 'Permission denied' and some files failed with 'Input/output error', but at least the bulk of the files did get copied across. However, I think that there are some owners, permissions or attributes that are not correct because if I try to delete one of the files that had just been copied, I am prompted to approve the change and have to enter my password. I have looked at the permissions using 'Get info' and they look okay.

My questions:

- Is there a way to get 'tmutil restore' to not crash at the first failed read, but continue on, as 'cp -R' does?

- If not, is there a combinantion of 'cp' options that would do a clean restore including setting the owners, permissions and attributes? I had thought of using 'sudo' in front of cp but thought that that would give me files that were owned by root (not what I want)

- Is there a smarter way to restore from Time Machine to an external drive?