David,
I know the guys all set the CG on the Storms here using a digital postal scale (they always borrow mine) About $50 from Sam's Club.
They set the mains on something about the same height as the scale (usually two ECU terminals) and the nose on the scale and balance until XXX pounds is shown on the scale. I want to say it is either 2.0 or 2.1 pounds but I have to ask someone to get you the right number. If the CG is off the Storm bounces like a bad kangaroo on landing. When its right they just roll on. I think I heard Alberto is out of the country, not sure if he is back. If you can get ahold of him at Modellbau he knows the right weight. I will try to reach my friends tomorrow and get you the right information. They probably have the most flights on the Storms. I remember seeing one with the same type of seam problem but I vaguely remember the way the wing is assembled I am not sure they bothered to fill it since it is solid. Its been awhile so I may be wrong on that.
I will see if I can get you some help. I will PM you a phone number if its okay with my friend. He can probably fill in the blanks from the manual for you with his personal experience with the Storm.
Mark