They ought to just tell him he's working on a plane (but really it's maybe just an old washing machine) he won't know

Boeing's internal processes (in hiring and handling the obviously near-blind worker) sounds FUBAR'ed enough that they shouldn't be allowed to build dog houses. Let alone airplanes.

That said, a competent airplane manufacturer, having learned that they hired a near-blind machinist, should first try assigning him to QC. Put blackout goggles on him (totally blind), then see how sharp his fingers and ears are at spotting misaligned joints, "off" pitches when structural members are tapped, and such. At Boeing's scale, he might easily pay for himself just through changing attitudes of the regular production workers - who know "the blind guy" might be inspecting every inch of their work.