Trial fitted the skin.The spacer does not seem to adversely effect the fit of the skin so I riveted the control horn & lower hinge in place. I spent the next few hours fitting, removing then refitting the skin in order to make it fit as best I could. After the 4th attempt I was satisfied that it was as good as I could achieve then bit the bullet & commenced riveting. I had a lot of very much appreciated help from my wife & PGC over the last two days, thank you.