can tell ya by looking at your set up to move the elevator push rod out a few holes at least one from the end, then on the center hole in the elevator to start with, another tip when breaking servo arms off if you score them with a exacto knife they will snap clean off and will not leave extra plastic or take too much, to much can leave you with a weak arm and possible area for breakage leading to, lawn dart syndrome.
BTW when I mentioned the rubber engine mounts I did not mean add some rubber from a hardware store or anything like that, they are specifically for mounting RC engines and are offered on Hobbico planes like the NEXTAR the mount that you had looks like the one offered on that plane thats why I mentioned it.
good luck on your test/maiden flights