Nice work. The hollow tops on K, Q and R look great.
Is your nephew much of a chess player? I hope he is and has enough respect for his pieces to not leave them lying around to get the tops broken.
I imagine that if it survives the first few years it'll be a set he'll be very happy with for a long time to come.
This is beautiful work and must have taken you a long time to design and make. It's also far more than a chess set, because of the motive you had for making it. I'm sure that your nephew will cherish it and so, in due course, will his children. Congratulations!
This was a design from the book The Art Of The Scroll Saw by Patrick Spielman. it was cut from pine spray painted and then varnished. My nephew plays in the school chess club so hopefully he will look after it. It took me about 4 months and alot of mistakes to get made but it was aloy of fun.