Finally put my eBay sourced Cole drill to use. I'm really running up
against the limited travel vs different drill lengths, finding it much
easier to move the head back to change drills. But then, how to realign
quickly?

With a 1/8 ball end mill, I milled a shallow groove down the length of
the column, to a width very close to the slot in the head. In aligning,
I have the clamp slot centered over this groove on the head and use the
base for positioning. Then, when I need to move the head, it's simple to
realign. There's more than enough slop in the whole setup to accommodate
any minor misalignment between the head and this groove.


Jon