Sorry to hear about your tank thats terrible.... Thinking on it from my past experience, it seems the reef tank starts off as a thing of beauty and then over a period of time it's inevitable of its decline. The odds seem against it over long periods of time, what could go wrong usually does. Unfortunately
I'm sure the liverock would come back
I suppose you could do a few things. 1 Leave the tank as is... not adding any more new livestock. That way you don't have to take it down and you'll still have something to look at
2 sell the liverock and hold on to the hardware. If you have a place to store it. In a few years you son will appreciate having a tank.
3 sell everything, and figure if you want to get back into it you'll buy all new (in a few years)
On the brighter side, one thing you'll never loose is the experience you've had. Which was keeping a reef aquarium
If it were me I would probably keep the tank as is and see what happened.