My commiserations Martin, that's an awful thing to happen. Tiptoe Too was on one of those Westlands moorings for a couple of years and while it was an absolutely idyllic spot, the way some of the large motor yachts on their way to or from Chichester Marina used to pass far too close, dragging half the water in the harbour as wake behind them, began to make me feel a bit exposed out on IC607. In the end I was hit too, although not nearly as badly as you: I came out to go sailing one day and found a large star crack in the hull amidships where it looked as if Tiptoe must have been T-boned, ironically (having just done a character assassination on motor boaters) - but luckily - by something small I think: The crack was about the height of a Laser or Topper bow. Your experience makes me wonder whether the Westlands mooring holders ought to lobby Chichester Harbour Conservancy for a CCTV camera on a tall pole looking out over the moorings from the Westlands hut, or maybe even one on a channel marker.
Anyway, I believe SL Yachting are the folks to go to for toe rails; their website says they'll custom-build any section they don't already do.
Very best of luck
Graham