BUT, AVAST created multiple Thunderbird (and Firebird) profiles.
When I extracted each named for sequence quarantined, the first Thunderbird profile was largest, 61KB, and subsequent profiles for as small as 1 KB.
I am assuming that first and largest is correct and subsequent profiles were created and quarantined because Thunderbird and AVAST were both running.
In contrast, the first couple of Firefox profiles were the same size.
Should the FIRST profile quarantined be the one to RESTORE?