Jay
The great thing is that you have made progress in increasing your score from exam to exam, except for the last one. Looking back on my test prep earlier in 2016, your scores were inline with mine. Have you attempted the ITTO exam that is in the simulator? That in my opinion would be a good gauge based on your score if it in the 80's . At the end of the day you are the only one that can make the decision as to if you are ready or not.
Good Luck!
Kevin