Well, no turning back now.  As a component of my "light" lugged frame, I wanted to use an S3 head tube.  One of the factors that contributes to its light weight is its .8mm wall thickness which results in the O.D.  being under size for the lugs. So I cut about .030 out of the lug diameters and brazed them back together.  They fit nice and snug now.  A lot of work for one ounce on these beautiful Llewellyen XL lugs.