To obtain a NOR gate, you only need to add one NOT gate behind your OR gate.
To obtain a XNOR gate, you need to add again a NOT gate behind the XOR gate. This circuit you cannot build since the C-MOS IC 4011 provides only four NAND gates. But it certainly has become clear that you can actually build all the gates only unsing NAND gates.
In the next experiment you compare how you built the basic gates using NOR and NAND gates. You will notice some striking similarities.