There is more than one artist using the name Anvil:
These are photos from concerts where Anvil played, so they may be of other bands that played the concert as well.
Monsters of Rock 1982 Aug 21, 1982 Castle Donington, England, United Kingdom Uploaded by Mister T
Event Programme
Status Quo / Gillan / Saxon / Hawkwind / Uriah Heep / Anvil Aug 21, 1982 Donington Park, England, United Kingdom Uploaded by Jim Jones
Ticket Stub
Status Quo / Gillan / Saxon / Hawkwind / Uriah Heep / Anvil Aug 21, 1982 Leicester, England, United Kingdom Uploaded by Michael Baty