Nura 150w lamps with interesting etch

I found this old trio on Ebay recently, believing them to be nothing special besides old 150w lamps, I was surprised to see they have "HCC" stamped above the etch. In the past, it wasn't uncommon for there to have been GLS street lighting installation so I suspect these were made for a council (with the "CC" probably standing for City/County Council) - they are also 250v so would have a slightly longer life.