Hi Motherbear, there must be a way of getting round this or some sort of reconstruction, picture rails etc. I've got a massive 5ft carved mirror that I shipped over and wouldn't even be allowed to screw it into wall but fortunately, there is a large mantle shelf so I've got it slightly leaning against the wall on top of it.... okay so you need to be 7ft tall to see your face in it but sometimes, you just don't want to see your face do you! ;)
This is part of the reason why I can't wait for us to be able to buy a house some day so we can do what we bloomin well want to do..(even if the wall does cave in ;D :-/