Are the top bolts shown on the topo on page 295? It shows 2 bolts but no route below.
Where would it be on the pic on page 293?
Nope, page 295 has nothing to do with this rappel. The rappel as it used to be is shown on the topo on page 292. One rappelled from the top two bolts of Hook and Drill to the ground with two ropes (about 160 feet).
I descended from the Balconies this way after the first time I did Lava Falls (as I've said before, Lava Falls used to have a one bolt top belay well back from the top - one walked off to rap Hook and Drill with two ropes after climbing it).
So go back to the topo on page 292. Add in a foot-wide ledge and a two bolt anchor just about where the letter "s" is in the word sling; maybe a little left of that. That's where Factor's anchor is. It was a smart and good addition - the rap can now be made with one rope (I think a 60 meter).
Unfortunately he put it in a few months after the book came out and so no-one knows about the additional anchor.
(And BTW, the new anchor isn't "on" any route, so there is no question of him having added bolts to a route or anything like that.)