I ran into the same problem the other night on my 60 size Seagull Extra 300. The belly pan did not fit right. I measured the wings from the fuselage to the tip and one side is 1/4" longer than the other. I doubt it will hamper it much but it is not an ideal situation. I think maybe the Vietnamese builders were having an Opium party. I got the belly pan on and had to add 1/4" to it because it was too short also. It don't look all that bad and I didn't really feel like building a new belly pan for it.
As for yours it won't hurt anything it just looks bad.

WCB