The demo panel now sports a working D-Latch flip-flop that includes a led driver in the form of a Buffer gate on the Q output. You might notice that the NAND gates have had their CdS voltage supply resistors removed. These NAND gates as wired do not need a voltage to indicate a ONE output. Indeed the output can be a floating 0 volts and still count as a ONE unless the following gate is either a OR or NOR gate. It is the ground connection that makes a firm ZERO output do the job. That is why I am using a Buffer for the output Led indicator.