Do you have an LDAP server directory added to Thunderbird in your "global LDAP server preferences"? Do you see that LDAP directory in the Address Book window?

I do not have an LDAP server identified in Thunderbird Preferences. In the "Composition" section of these preferences, Local Address Books are selected (NOT any address Server).

         But I cannot "find" any local address books to look at or edit (the Mac Contacts app show no files)

However, in the "Account Settings" for my mail account (which is using a comcast POP mail server), the Composition and Addressing section shows the attached request for the LDAP server.

BUT My biggest concern is that I want to edit the address books (presumably local), but I cannot find them in any user directories.

There's something wrong with your setup, as the Addressing preferences are missing the Local Address Books (see picture). The Address Book should appear under the Tools menu, or Cmd+Shift+B. Does the Preferences page look different in safe mode (hold Option when launching TB)?

Thank you, sfhowes and Stans for your replies & suggestions. As sfhowes suggested (politely) I should have looked more closely to the TOOLS menu where lo and behold, there IS an address book tool and it knows my local directories (and where they are ;). It gives me what I need to edit 8 years of accumulated subdirectories. One might think that with covid lockdown upon us, I would have nothing better to do than edit these directories ... Thank you for the wake-up guidance..