Tailstock alignment process

I turned a cylinder of stainless steel to the identical outside diameter of the tailstock spindle (39.98mm). Then brought the tailstock spindle up against the just-turned cylinder in the chuck, locked the carriage and locked the tailstock and tailstock spindle. Then, using a tenths-indicator mounted to the apron, I could adjust the tailstock lateral position to be coplanar to the just-turned cylinder.

Done