Momentary-Pushbutton Latch Switch with off delay?
Good news, I have hit it with a stick a lot, made some guesses, then some changes and have managed to get a result... 

I couldn’t get the existing flipflop to work without the timer so I looked at some CD4013 on-off circuits online (and built one to make sure my components weren’t faulty).  The result being I combined the flipflop I built with the circuit provided by Jonk.  The timer circuit is the same, but the flipflop C2, D4 and R4 area is now a bit different and I have grounded pins 4 and 6 on the CD4013.
LED 1 and R6 don’t have an impact on the operation; they are there so I can see when the flipflop switches.

When the circuit is off I am seeing the base of Q2 sitting at 11.27V (collector at 0.01V) and when the button is pushed the base drops to 10.95V (collector rises to 11.65V).  The power supply is stable at 11.8V.
In its off state (standby) the circuit appears to be consuming about 21mA including LED1 which is on when the circuit is in standby.  When active it consumes 87mA which includes the relay and 2 LEDs indicating the relay has switched to the NO pins.

I am interested to hear if this circuit can be improved and/or if the Volts and mA I have recorded are good or could be better...

Thanks.

Edit; I have found the circuit switches on and switches the relay when the power is connected.  The flipflop and timer delay work correctly after that.
Is there a way to prevent the self starting with power on/the main power supply is connected?