Trial fit of vertical fin showed a problem - it does not fit.... I checked online manual for answer but it was not explained. Various searches of other builders web sites solved the problem - thanks guys.... The rear spar flange needs to be trimmed back (including removing the last hinge knuckle).
A picture tells a thousand words.
The vertical fin needs trimming to clear top of turtle deck, this was slowly done until a 3/16 drill could be used as a spacer.
