There was some space in the day so I started getting some of the sanding out of the way.

We have no special trick for tips. I scribe the center line on the tip, razor plane them until they have a nice basic form and then smooth the planing flats into a nice curved surface. It's a combination of sanding and looking and sanding and looking and, you get the idea. Anyway, nicely rounded tips that are even between the two stab halves. Some people prefer a larger radius, some more narrow radius. I'm not sure if it makes a difference aerodynamically.

Here is a photo of the finished tip. Now when I chop off the elevator, the tip will flow smoothly from front to rear.