Thank you all for your informative posts!
Sorry for the delay in replying, part timezone (New Zealand) and part work getting in the way of a hobby :-[

Probably a newby mistake but I didn't stop to think past joined arcs for making the curves, a Freeform curve with control points is surely going to be a lot more 'Bezier' and smooth.

The lines under the fus would certainly be caused by the method I used to create that 'cutout'. What I did was import an airfoil closed curve (PW51 if anyone is interested) and extrude it. The problem is to import, I used a PDF print of a DXF airfoil-plot. This method I imagine created micro-steps in the foil surface which would have transferred to the fus during my Boolean>Merge. By the way, I take it a DXF Import is not currently possible?

So I shall start from scratch (want to change the shape a little anyway :-]), use Freeform curves and build the airfoil-solid by drawing a closed curve over a JPG image of the foil plot and extruding it.

Will also play with the Rebuild command.

Cheers and thanks again.