Homer's two gifts... and two pivot centers

[Martee]

I understand your confusion, Martee, and it gets worse...

In addition to the Horizontal Hinge Pin label you see on Sketch 1-L, you also see an Angled Hinge Pin. The labels are indeed clear, and they are seemingly in direct conflict with my post stating there are only vertical pins. What's going on here?

The key is in how you read the words:

HORIZONTAL HINGE pin...the (vertical) pin of the Horizontal Hinge. Not a HORIZONTAL hinge pin.

ANGLED HINGE pin. The (vertical) pin of the Angled Hinge. Not an ANGLED hinge pin.

Drawing updated, at least I understand what is being said, still think 1-L needs some work...