The guy was from Norbury, and in continous dispute with one public body or another. You're right, the tank was parked for a time on Acre Lane (I think he may have had some business operating in what is now the used tyre place), and had various colour schemes. Last I saw it, it had broken down or run out of petrol by Kennington Park, returning from haranguing the crowds going into an Arsenal Match. That was a couple of years ago.
He seems to have had an especial relationship with Brixton police.
Police pay out for pig-parking prank