Is there a record of previous UCS restores?

you may check log files.

e.g.

[root@B3900-R66-S14:Active:Standalone] config  grep ucs /var/log/audit
Apr 10 23:15:32 B3900-R66-S14 notice tmsh[24151]: 01420002:5: AUDIT - pid=24151 user=admin folder=/Common module=(tmos) status=[Command OK] cmd_data=load / sys ucs /var/local/ucs/base.ucs

[root@B3900-R66-S14:Active:Standalone] config  grep config\ install\ operation: /var/log/ltm
Apr 10 23:15:13 B3900-R66-S14 info tmsh: Begin config install operation: /var/local/ucs/base.ucs