The spindle sanding is the safest operation. I thought that was the problem and that you were doing it with a router. You could make a holding jig that would allow you to use it to push the ears through. I would use a board with 3 or 4 screws sticking through about 1/8" and put a handle on it. The pin holes from the screws would be sanded out when you use the spindle sander. Use screws with really sharp points like drywall screws. The ones that usually come in spar packs are about as dull as butter knives.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.