Update 4 May 2013: Both of these boxes have been removed, and only bland greenish plain boxes remain.
Yes, some control box murals have survived in Avondale. Here are two examples. The first can be found at the "Peace Garden" apex of the intersection of Ash Street and Great North Road.
I'm still not entirely sure what it's supposed to represent. A steamy tropical in some place historical, with a glass jar? It looks cool, anyway.
The other is chipped, tagged and faded an intersection away, this one where Ash Street meets Rosebank Road. The dogs' eyes look somewhat spooky ...
I suspect the dogs and the men are based roughly on this part of a photo of the old Avondale Hotel (ref. A4024, Special Collections, Auckland City Library, published in Challenge of the Whau.)