I remember when you started this project. It is turning out great. You have a lot of info in this thread to help you through this.
Don't worry about the seam allowance. As long as they are consistant through the project , you should be fine.
The only thing that will change in the end is that the finished top will be just a smidge smaller than what your instructions call for. Not a problem.
This is going to be awesome when finished!
Keep posting your progress!
peace