For what it is worth, removed the rear passengers side hub today. The attached ABS Ring, or tone wheel (part #26750PA010) fell off in two pieces. None of the bolts (part #901120077, 4 required) that attached it to the hub were there. This car had the bearings replaced 4,000 miles ago by the Subaru dealer it was purchased from, and who maintained it?
Went by local dealer, 3 days to get, $195.06 and, they said, only 5 left in the USA.
First side, first set back.
To add, this is a '94 Pearl White I recently purchased knowing there was a wheel bearing howl coming from the back. The seller, I believe, was totally honest. Besides the easy stuff, the work is actually being done by a reputable mechanic.