Restore GPG key files from tar?

Before I wiped my partition and installed Red Hat Linux 8.0, I backed up
my home directory to with tar. Now that I have things moving and am
staying with 8.0, I want to restore some of the files from my backup.

I was using GPG and had generated keys for myself. I don't know what
file the keys and/or keyrings are in inside the tar backup. And, as an
aside, I am not sure of the tar command syntax to extract specific files
from the tar file. I don't want to just extract it all, only the files
that I need. Any hints?

Alan