The other clue is in the gridpoem on 2993...

Can you guess my source material?

It is by a famous 20th century painter. I have altered the hue slightly...

...gridcosm?level=2992 ...gridcosm?level=2993

Also, my apologies to SRD for not blending on what was a perfectly good leave, but to be honest between his image and the rent comment in the gridpoem, I think that's what set me off on the quest.