Thanks for the follow-up. I was able to get the thing apart and learned a thing or two. The most surprising thing is that the faceplate for the LED readout for the Sony RF CD Changer (that I am installing after having removed it from another car)is exactly the same size as the cassette holder inserts. Thus, I now have what appears to be a "factory" installation. Further, the cassette holders separate (non-destructively) from the portion of the insert that has the holes for the two screws that hold the assembly in place.
The ashtray and cassette holder are clipped together. I ended up removing both together, which required removal of the center console (two screws under shift gate and two screws at bottom of center storage compartment). However, after removing the two screws under the radio, I could have slipped a knife or some other piece of flat, stiff metal in between the wood bezel around the ashtray and the black plastic bezel around the cassette holders. This would have pushed the ashtray and cassette holder asseblies apart, unclipping them, again non-destructively, and pulled the cassette holder out.
Don't think that I would have gotten it apart without your help.