I have "drilled" one of these cases. If you drill them the standard way you basically uniformly enlarge the existing hole which quite often will get ugly on the super thin lugs. What I did was use .050" carbide end-mills to relocate the hole just a bit to get it away from the top edge of the lug. It turned out nicely but was somewhat expensive as it took 2 end-mills as they are 1 - very small, and 2 - very brittle. Even relocated to where they don't break out the thinness of the lug makes 'em look a bit strange, to me anyway...