Hi Andy
My Sea Queen was built from the new Jontika CNC kit 3-4 years ago, it came with an 850 size motor and a large 3 blade prop, I enjoyed the build floated it twice and it was put up the loft, eventually sold to a guy called Nick who came down from Yorkshire and bought it . The attached drawing is a photo of the original Aerokits plan, with the scale pencilled on, the boot topping I've drawn on its around 1" up from the base of the transom, the stand it's sitting on is made to keep the boat level so the waterline can be drawn on with a block of wood & felt pen
and masked for painting. Hope this helps 
Regards Ray