The side panel on my bath is like a sheet of black glass. A builder friend has told me it is called Vitrolite, made at one time by Pilkingtons but no longer available. At least one of the Mersey tunnels used to be lined with it, he says. The panel has a fracture in it. I could ignore the fracture, but I need to replace the taps at some point and the panel will certainly come apart when it is unscrewed. Any suggestions what material I could replace it with? I'm looking for something that approximates to the flat glassy look of the Vitrolite. Dimensions are 1840 * 550 * 8mm.