If in fact that damage is from your fist and not being so mad you forgot to plug in your ailerons of left the rx wire wrapped up.
You should take up another hobby... shrewwweeee!
Breath in and hold ten seconds next time.
After all they are Almost Ready To Fly!!!
I would buy another one and build it as per the instructions.
That is how it was designed. I have all of the 1/4 scale H9 ARF's and love them all, never had one problem, do make some changes though. I think you should give the P-51 another chance. This time quit trying to re-design the model and go fly it.