Porcelain Down Under?

We've been traveling in Zew Zealand for about 2 weeks and have looked everywhere for Porcelain signs with zero luck until yesterday when we happened by this old gas station and saw this cool "Paint over"sign. I'm pretty sure it's a CalTex under the paint but no way to really know. I'm amazed at how rare porcelain signs are down here? They certainly needed them as it rains a lot, but I believe they must have recycled them as they were no longer being used? Interesting that the local Antique dealers had no idea that this sign was actually a gas sign and probably porcelain since it isn't rusted under the paint. Too hard to get it home so didn't even inquire if I could buy it.