Select Help/Troubleshooting Information, click Open Folder to open the profile folder in File Explorer. There you will see abook.mab and history.mab, which are Personal Address Book and Collected Addresses, respectively. If you have an abook.mab or history.mab from a backup profile, you can copy them into the profile folder, overwriting the existing files. If you want to keep the current address books, first export them to LDIF files (Tools/Export... in Address Book) and then move the mab files outside the profile before you copy in the backups. Close TB before you copy in or move out any mab files.

I downloaded from back up disc and now have T-bird 60.9.0 32 bit and it says up to date and my email addresses are back. I tried downloading 68.1.1 and I loose my email addresses. I have saved the 2 mab files and will see what happens.

I recommend you stay with TB 60 until the update to 68 is offered from within TB 60 (not from downloading the 68 installer independently).