Hi Paul
The servo rails for the elevator and rudder are very simple to construct and install . The exact placement of the rails is not critcal . By placing them as far forward as you can you will reduce the amount of weight you will need to add to the nose of the aircraft for final balancing . The fuselage formers can be difficult to get placed perfectly in position ,but they only have to be reasonably close . The sanding of the planking of the fuselage will be able to hide any reasonable errors int placement of the formers . I built my fuselage using a jig for careful alignment of the fueslage and because of the size of the formers they tend to warp a little , this appears as a slight misalignment from various angles but the overal placement is correct .
I wouldn't be to worried if yours has the same effect.