I reached out to Apple for support, and of course, Apple suggested I contact WireGuard for help (no surprise here).
While holding for an Apple representative and using "Google," I discovered that WireGuard stores tunnel configuration inside Keychain.
Back to my TimeMachine backup ;-)
/Volumes/G-DRIVE mobile SSD R-Series/Backups.backupdb/mbp/2023-03-15-160527/APPLE SSD - Data/Users/user/Library/Keychains
% file login.keychain-db
login.keychain-db: Mac OS X Keychain File
login.keychain-db with Keychain Access, then searched for
WireGuard and voila!
Then, use "copy password to clipboard," to copy each tunnel configuration into clipboard, then paste it into WireGuard and the rest is history!
ALWAYS make a backup!
To be fair to Apple, the representative did share following document with me that help me find the right file and resolve my issue)
Copy keychains to another Mac - Apple Support
Thanks to everyone (including Apple)!