If you are going to use all 70's components, why not just buy a set of Campagnolo verticals from John Barron at Velostuf (he had lots) and have the builder file them well and braze in a washer to thicken them up as a few builders did back then around the axle.
Ohterwise, I would inquire about Bruce Llewellyn's investment cast units that look quite nice. I would just have Bruce make a whole frame, but that is another subject.
>From your text you are looking for a reason NOT to use horizontal units.
I think both can be linked via the CR website.
John Jorgensen
Torrance Ca USA