Interesting that it is a 1942 serial number, but it is a loose change gear machine instead of quick change gearbox. That implies that it was built for the war effort, and expected to live its life turning out a single part, where feed rate or thread pitch were not often changed. Looks like all you are missing is the reverser, change gears, compound, and some covers. All those are replaceable. I think you might spend less money putting a QCGB on it than finding the gears, however.
allan