Concensus of those hearing my description of the aluminum bits found stuck in a tranny valve is that the piston that pressurizes the 2/3 shift and reverse lost the flange/rim around it. Picked up the car and drove back to work and then home. Slipped a bit but was much improved. Next day (yesterday) I made it about a mile from home and lost all forward gears. Drove back home in reverse (to some interesting looks). Took only a couple of calls to find three different used transmissions, all $350-450, so car is dead until I can arrange for delivery of the replacement and find someone to install.