the real question is, do you really need to take 5 or so grams out of the nose on a profile plane? The holes may very well accumulate more than 5 gr. of epoxy when you glue the mounts in. I'd really question this. If you reallly decide you need to get rid of 5 gr. up front, take a belt sander and take a few extra strokes along the the plywood doublers to smooth, round, and fair them in. that will take off the extra weight quickly and easily and add some pretty curves besides.