The gudgeon pin on the Westbury Wyvern is exactly the same and I too have puzzled over the reason for it being hollow, especially as the brass end caps are also drilled 1/32" diameter. It is obviously not for lubrication for the little end because, as Frank says, there is no cross hole for the oil to reach the bearing. I assume, as Jason says, that it is for lightness but, if so, what is the purpose of drilling the end caps?