Hi,
I’m building a Guillow P51 (#905) from the same series as your chipmunk. I’m on my third try for the fuselage. Alignment is a problem for me too.
You might try cutting the sides of the fuselage from a single sheet of balsa. The sides that came in my kit were not well match. One was more flexible than the other.
Also, I’ve been experimenting with using magnets instead of pins. The advantage is that magnets can be placed on you building board so they stick up vertically and provide a true right angle in 3-D. I purchased my building ‘board’ from Lowes in the sheet metal area. I also purchased magnets there.
If I had it to do over, I would probably purchase a product called ‘Magna-board’ from Easy Built Models (see
http://www.easybuiltmodels.com/b04.htm ).
For this model in particular, I tried using ceramic magnets that are about 2 inches by 1 inch by 3/8 inch think. I can put the 1 inch by 3/8 inch surface down so they stick up 2 inches. But the magnetic field of these magnets is so strong that they tend to snap together if they get within an inch of each other, especially when they are standing up.
I found some 2 inch corner braces (see
http://hardware.hardwarestore.com/28-44 ... 03299.aspx ) in my junk drawer in my garage and glued them to the 2 inch by 1 inch surface of a few of these magnets.
This arrangement is more stable. Placing the largest surface of these magnets against th Since the corner braces are steel, I was able to align them with the outside edge of the top view of the fuselage drawing that comes with the kit. Then I used a much smaller magnet (1 inch by ¼ inch by ¼ inch) to hold the fuselage sides against the corner braces. The magnets worked great. You can nudge them around until they are in the perfect place.