Ok, as I was preparing to get started brushing thinned CWF on the fins of my group-built rockets, I happened to note that some of the end grain edges of the Big Daddy fins were in pretty sad shape.
This of course, was a result of Estes' not-so-great 1990s' era balsa sheet die-cutting process.
I had to set to work with spackling on some thicker CWF to fill the gaps and holes, and sanding the edges smooth.
Now things are in proper order, so I can get back to grain filling and (sigh).....much sanding.