Hi everyone! I'm building up an old '72 Schwinn Varsity with my sister for when she goes to college as a graduation gift. I've got most of the parts down, but the one thing that is still confusing me is the headset size. Unfortunately, I do not have the original cups and bits, which I would have otherwise reused.

Sheldon's explanation makes it seem as though I have to buy two or three different headsets, then mix up the parts so that everything fits. Do I need to do this, or can I just buy a BMX 1" threaded headset? Or a standard 1" threaded headset?

Help please. I am totally confused by all these silly Schwinn anomalies!