Meeting BoB Spit pilot and Rigger

For the rigger:

A couple of days ago I saw a entertainment documentary about the delivery of a Spitfire (later modell with invasion stripe markings) to the US. A British pilot did the last check and tuning flights with the Spit in the US before handing over the keys. One of the tuning work done was to slightly bend the left corner trailing edge of the right aileron upwards (using a pre-formed wood block that the pilot held with his left hand on the upper side of the aileron where the bending should take place and with his right hand he held a hammer and thus hammering the bottom of the aileron trailing edge of the Spit and thus incurbing this part slightly upwards). The objective was to modify slightly the airflow there so that inflight the airstream would timidly pull the aileron from neutral position down thus countering the right roll tendency encountered otherwise. The pilot said this was described as a procedure in the handbooks. I would like to know more about this. Can this be confirmed by the rigger? What where the commonly applied procedure?