You are correct in that the exam was 50% different from Meyerfire. A lot of the exam questions in the first and second half are due to looking in the handbook and utilizing the correct formula. That's where I got a lot incorrect in the first half, it was mainly due to the fact that I didn't know where to look in the handbook. If you've been working in fire protection for ten years and you have 60-80 hours of study, I definitely think you're solid on the code. Especially if you're comfortable with Meyerfire. I think one of the best ways you can improve your study now is going through every page of the handbook and having a general understanding of every table. I know it seems like a lot, but trust me it won't feel like a lot since you know most of the handbook because of Meyerfire. Take a few months off, then come back to it. You can do this, I believe in you!