I always think that honesty is the best policy when it comes to most things in life and that includes applying for jobs. This approach also makes things easier for you as you won't have to focus on hiding the truth the whole time. So this will use up less energy.
I believe that having already gained your CPL demonstrates that you can do it. If they give you the cadetship and the chance to do everything again then you have an opportunity to improve your flying skills. This can only be a good thing. However, I suggest that some humility is a good thing. What they don't want to see is arrogance....so what I mean is that you don't want to give the impression that you think you know it all and have nothing new to learn.
Good luck.
