My knowledge is limited so my design approach was to take the logic diagram of the D Type Flip Flop, build out each logic unit with discreet components then link them all together and see if it works - Spoiler - It did :)
Although I do understand how this works, I am stumped as to why I needed to add the 1M ohm resistor to the output of the differentiation circuit. Without it, the circuit worked and I saw a nice pulse while the Oscilloscope was connected. As soon as I disconnected the oscilloscope probe the circuit stopped working. Adding the 1M resistor kept the circuit working after the scope was removed.
The circuit is limited to around 2.5kHz clock speed but it works and connecting Q Not to D provides the expected Divide by 2 function. Yes, there are a lot more components in this version compared to others I have seen but I am a beginner and I can follow this and understand how it works.