If my googling skills are working, my passport is a western digital external drive. So I must ask how does your information get onto it, as whatever makes the backups usually does the restore.

I believe I set it up to automatically back up anything new/changed. My Passport website suggests that there should be tabs with an option to Restore when I open the external drive but there are no such tabs, just a lot of files.

I did find the files with all my Mail info - emails, possibly contacts, etc.

But I'm wondering now if I have to get my computer to recognize the "My Passport" in order for it to allow any restoration? But is there anyway from Thunderbird mail to reach out to the external drive and move that information (emails etc) over?

No there is no facility within Thunderbird. It will either have to be done completely manually, or using the restore options that come with installing the "my Passport" device and it's attendant software.