Thanks for your help. So i need to turn the covers 180 degress so that the R, L are underneath .
Thinking some more : left - right transposed but numbers uppermost will be the same as the correct left - right , letters down. So i am now wrong ( letters up) and the dealer was right! ( but wrong)
I can not see any droop of the cover lines. They appear symmetrical
The Haynes manual says that at high revs the rockers will hit the cover. Surely this can only be when valve float is occuring, and you are in trouble anyway?