Brian, funny thing - just this morning as I was installing the plug on a bubbling return, the faceplate cracked (the funny thing is that I didn't notice the hairline crack when I removed the directional 'eyeball'). I muttered a few choice words, told my partner to stop blowing out the lines, and went and got a #3 Philips head screwdriver and ... a new SP 1408. The changeout was made underwater, as all the ones I've done are, just be careful not to drop the screws and don't overtighten them when reinstalling - overtightened return faceplate screws will crack the faceplate. On the other hand, undertightened screws can cause a leak - don't 'power' the screws in, turn them until you feel resistence and give just them a small 'snug' turn, they should recess a little into the faceplate, but not too much.
One other thing, if it's an older pool the faceplate may be a SP 1411, which has the receiving threads in the faceplate, not the wall fitting.
I'm sure that you can replace just the faceplate and have no problem with it anymore.