Steve Evans 2

Hi, I recently resurrected an old Archie biplane that I built in the late 80s from the depths of the loft. It has been well stored and has no warps in the flying surfaces. It seems to roll faster to the right than the left even though the aileron control throws are equal. It has ailerons on the bottom wing only. The C of G is within the recommended range. It also tends to drop its nose more in a right turn then a left. Loops however track straight and true. Any ideas how I can trim this out? Cheers Steve