My brother, Tom, clued me into this method. He even sent me an oscillating Dremel tool. I cut some beautiful slots with it that fit the hinges perfectly. A couple of days later I was going to glue them in, but the hinges were a very (too) snug fit. I'm guessing that the tool "mushed" some of the balsa around the slot, which later relaxed. It was easy to open up the hinge slot with a fingernail emory to perfectly fit the hinge, so I still like the method. I don't know if this is typical with using an oscillating cutter, but it's something to be aware of.
Rick