I think Lordship Lane station is where the housing estate now is on London Road.

There's a good article about the Crystal Palace to Nunhead line with some modern photographs on:

http://www.abandonedstations.org.uk/

On the site just scroll down to "Disused London Overground Lines" and it's under "South London"

The station would have been located opposite Hornimans Gardens, positioned roughly between the gardens entrance and Wood Vale.

As a child I can recall the rail bridge crossing London Road at this point, the line ran parallel with Wood Vale between the back gardens of the houses and the park.

I've been looking hard at the painting to try and see if there is a bridge in the distance, but unfortunately can't see one.

The Moore Park Hotel and langton Rise would have been further along the line, nearer to Honor Oak Station.