I did not have a 1/4" drift pin so I machined and old drill bit to a point on the shank end to achieve the same result. After assessing many different ways to drill the eight holes, I decided that easyest way was to remove the base plate from my drill press and lay it down on the bench. I then clamped the leg to the table top with regular G clamps and tapped the gear leg with a wooden mallet to move it exactly into position.
Lucky I only have a small drill press.
Marking the centers for the axle bolts
That 1/4" drill bit is my center punch, the other end has a point