This TRACO CABLE vintage magazine ad underlines about the PVC cables and wires. It gives the info as
"TRACO" Cables are laid by Posts and Telegraphs Department to provide efficient service to their valuable subscribers. Not only by P & T but others like Electricity Boards, D.G.S. & D., Railways, Industrial Undertakings, Domestic consumers etc. have patronized "TRACO" for their requirements of PVC Cables and Wires, Bare Conductors, Telephone Cables etc.