Hi, I'm. After some help. We lost a section of fascia cover board in the wind earlier this week. So need to replace. The old [now broken] cover board slid into what I can only describe as a h profile piece of pvc. The top of the cover board slots Into the n and the l bit slips under the felt on the flat roof. But I can't find it anywhere to buy a new bit. Does anyone know what it's called and where it can be bought. Thanks Adrian.