During the first test flights Andy noticed that the slip ball was 1 width to the right. I had a balsa wedge from my model aircraft days so I cut it to the size inthe photo 1 (?" x 1.5" x 3/8" )and it worked perfect - zero slip between 130-150 kts IAS (my normal cruise range) - so lucky at first attempt.
When it came to painting Diana at Gloster Airt Parts kindly gave this loyal customer a free Avery wedge that I cut down to the size as the balsa one and Mick Allen my painter painted the wedge and then bonded it on. As you can see in photo 2 you can barely see it in the air in bright light.