If I remember correctly, last year the Dearborn Steel Tubing guys had a factory tach drive distributor (SK numbered if my memory serves me correctly) maybe give them a call and see if they still have it.
I'd just find an Accel dual point Tach Drive FE distributor and use that, It will be a lot easier to get a cable, tach. ect. Than the ultra rare ford unit. ( I think pertronix even makes a conversion for it...)
Nelson Specialties has a Ford racing unit XF part # very rare from LeMans 24 hour racer