This may be a little late, I didn't get a chance to log on yesterday (MIL in town overnight). Yes it's SP 1408, and any pool store that hase liner pool supplies should have one you can buy, without having to get the whole fitting.
Durring the short time it takes to remove the old faceplate and install the new one, some water will leak - but the force of the water in the pool will keep the liner ~sealed to the wall, so the amount lost is negligable. Good luck with the change out, if you need any more help or have more ?s, feel free to ask.