Thanks for the suggestions. I rather like the brackets behind the overiders. I was very interested to note that no-one mentioned the risk of cracking of the wings. I think I will go with bolting the lamps directly on to the wings using the rear facing bracket. That option seems to be the neatest since although the MMC brackets are certainly substantial it results in several bolts being visible. Mounting directly on the wings also gives an option of using a bracing bar behind the wing if necessary.
