This account is locked and can't be used (AppleID is not active)

Managed to get this fixed - the only solution is abandoning the locked/disabled account and re-registering the device with new/different apple id.

This required resetting the device by making a request to have the activation lock removed with apple. The request required the original receipt including the device serial number. I initially asked apple for this but they were unable to provide it as the order was too old and it was archived. Thankfully I managed to find the receipt in my email. If you dont have a receipt I'd say you are stuck. I also had to raise the activation lock removal request twice as the first one was erronously rejected as they thought it was a business device (it wasnt).

All in all this has been a terrible customer experience for a legitimate customer. Locking these devices this way with no route to resolve other than clearing activation locks is terrible. They may be trying to lock security down but its gone too far and is short sighted in terms of legitimate customers when its so difficult to get access to device again. A lot of people will have bricked/lost access to devices they legitmately own through no fault of their own.

For me I suspect this was caused by creating a new apple id on an old device, on the latest version of ios available for that device which doesnt support the latest security required by apple - they ought to prevent these types of accounts being created in the first instance rather than allow it and subsequently lock/bricking the devices.