Coopers pre 1700 (General)
Men in Armour for Gloucetershire 1608
doesn't list any COUPER/COOPER in Engish Bicknor -
At least it does show where this name existed.
Mitcheldean: has Thomas COOPER/Rise COUPER/William COUPER
Tried looking for Cooper Wills on Ancestry - none for English Bicknor
If you put a % in the surname : and just search for OCCUPATION: Miner
The only Miner at English Bicknor was John RAWNELL - A40 (age around 40) - Again this surname has been written in different ways on the Forest of Dean records.