Vintage Radiators in Leeds make new P and J type radiators, it might be worth a call to see what he has available. Tel. 01132872946. He rebuilt the whole of the bottom end of my radiator and it is a perfect match to th original ie. Mounting bracket, Cast bottom pipe and drain tap. I believe he did a display at Stoneleigh and had a J2 radiator on display. May be someone out there can confirm the quality of his work. Ask for Tony.