I just purchased an Apprentice from Hobb-e-mart on ebay that is a RTF but missing the foam insert on the bottom of the fuselage. I don't see it in the parts listing for the plane at Horizon and was wondering if it is needed or can a simple modification take care of it? I have a couple dozen planes and helis, I just like the size and looks of the Apprentice and have been wanting to buy one. Thanks for any suggestions or help.