Basil Jet writes:

The direct (hahaha) service via Denmark Hill got replaced by the
Overground. The service from London Bridge - Sydenham - Crystal Palace
-
Victoria still runs, hence the six hour comment above.

And if some unsuspecting visitor were to catch it all the way using
Oyster PAYG, would they just be charged a Zone 1 fare, considering that
the journey is within the 90 minute maximum zone 1 to Zone 1 time.