A friend has given me his iMac to sell, its a late 2012 27 iMac, purchased from JB Hi Fi.
When I set it up I went to have a look at the Serial Number and description but noticed it was missing.
Any ideas how this occurred, it has not been repaired. The serial number is on the base so I can verify it
From googling it seems I have to take it into Apple to get this fixed.