Definitely check the rigging of the ailerons as well as the flaps. And, the flaps have a unique bushing on them that are asymmetrical. If one of them is replaced with an incorrect bushing, it may be a cause of your issue.
Also, since you have a D model 200, check the spring for the aileron trim which is under the front seat. Either remove the kick plate below your front seats, and/or remove the seats themselves to get a better look.