Level flight requires slight right hand turn input

[B2C2]

So as a final update I finally got to fly the plane after adding this 1/4 inch of upward right aileron adjustment on a calm day and it now flies a straight heading with no control pressure input and neutral trim tab settings. So thanks for the help and of course RTFM. The yoke is still slightly rotated to the right, in level flight, but no control pressure is required to maintain a heading, so at this point it is purely a slight yoke position adjustment which we can take on at some point in the future.