I can't see the next time I will use a 15.25mm bit

I have a sorry 3/4HP import floor drill press that isn't fit for precise milling. I had woodworking in mind when I purchased it. The head has some play in it, so got some 1 1/2" thick ash to use as a jig to locate the new holes. I drilled 2 holes in the block so the block would slide down on 2 of the original lugs. I then drilled another hole in the block where the new hole for the studs would be and used that as guide as I drilled the new holes.