I dont see anything holding your fuel tank from sliding backwards(unless I just cant see it). Vibration can cause even the tightest tank to move,so dont take any chances.

Also,it doesnt look like the the wooden blocks that your cowl screws too are reinforced. I always make sure to goo a large amount of epoxy on 3 sides of them or even epoxy some 1/4 round wood on the 3 sides. I think every plane I ever had that I didnt do this on lasted about 2 flights before those blocks broke loose.

Other than that....its looks great!