It would be a very easy exercise to put an accurate hole thru it, and put a morse taper spigot in the RT yourself. The sticky up plain bit between the thread and plate, and the bottom of the base plate are your datums for concentricity.
It definitely looks like the holes are too close to the centre mounting, but it would be easy to drill holes in the other axis. If you are fitting a centre spigot, it wouldn't matter where they were.
Bogs