Well 2manyrads, I'm not really sure what the Top Star is worth but we have Forum members that excel at sleuthing out prices so maybe one of them can offer an opinion. I don't think there are a lot of Klira's in the US. Klira certainly exported, but it's always been my impression that most of the instruments in the US were brought back by servicemen stationed in Germany.
If I were in your situation, I'd put the Top Star in the case and in the closet. I'd then take my son out guitar shopping and let him pick out a brand new Squier Statocaster or something similar for around $150, a cheap digital effects box and a small practice amp like a Line 6. I think this rig would give your son optimal conditions for determining his level of interest in the guitar and if he learns to play you can pull the Top Star back out of the closet in a few years and let him experiment with a hollowbody.
Old guitars are finicky and usually need work to play properly. The Top Star is also probably a bit too big for your average 11 year old. I think your best bet for nurturing a musician is the Squire and the effects box. Kids love the sounds they can get out of the effects processor. It makes even playing on one string fun