[Vic Piano]

When you say the center section, are you referring to the "banjo" or the housing for the Columbia gears? Also, the Zephyr (when ordered with a Columbia) had the unit installed at the factory so, could it be that (for the Zephyr) Columbia cast both sides and delivered it to Lincoln already assembled as a unit? That's just about the only thing that would explain the roughness of the castings...