I have made some other progress. According to the pictures on the Toyota dealer's database, the pulley is identified as part no. 16604A, and this looks like the assembly including the bearing, snap-ring, grommet and proprietary shaft. They want 93.00.
A simple google search matches this 16604A to 16604-76010, however, all suppliers call it "SPRING (FOR IDLER PULLEY TENSION)2TZFZE..TCR10, TCR20"
There is no "spring" in, on or around this part. Trust me....
Still determining if the part is pressed on, or just frozen from age and corrosion/rust.
I guess the downside is that to use a pressed pulley puller, I have to remove several more parts. Ugh.
I have uploaded a parts image in the files section of the Yahoo Previa group. Pulley 16604A is at the bottom, just over half way to the right side of the image.