Depending whether or not the trigger is set from the high-to-low pulse, or the low-to-high pulse, just take the ign line and NOT gate it or feed directly. It doesn't need a pulse, it relies on the high/low or low/high. So if you continuosly feed it IGN, then it goes from 0 at start to 1 all the way until you shut it off, then the 1-0 stage will trigger. I think this is the stage you want. High to low. If you want low to high, then just NOT gate the thing to ~IGN, and you have 1 at beginning, 0 until you shut it off, and then the 0-1 stage triggers.