You may even be able to remove your servos in the tail, and slide a piece of thick balsa into place, glue it in, and then slide the battery and foam in over that, and lock it in place with either a tie wrap, or a velcro tie wrap. I cut in a hatch too far forward, and need to move my battery back further, so thats what I am going to try. The hatch I did cut in, I didnt replace the wood sheeting. I had two pieces of balsa spanning the fuse for strength, and just monokoted over the open hole. Couldnt tell it was there unless I pointed it out.

Steve