Hi
Last time I looked the plan clearly showed the rudder well clear of the stern. The prop shaft was much further forward than shown in your latest post. The problem is the rudder post will be too near the transom stern to allow you to fit a linkage to your servo.

You need to mark on the hull from the plan where the rudder should be fitted and fit it then adjust the prop shaft to the correct position.
Not sure how much room you have between the prop and hull but one solution would be to remove the propshaft and bearing then cut the prop tube and skeg so that there was enough space for the rudder and refit the bearing and propshaft.
The alternative is to unglue the prop shaft assembly and move forward to give the space.
I believe you used the plans to set the slot in the hull so it should all fit.
Sorry probably not what you wanted to hear but your present layout doesn't allow for rudder control.
If you wan't to discuss please send me a pm and I will offer any further help you require
Dave

Sanded off the K 3 and will apply filler tomorrow. installed prop shaft assembly and short skew. Removal of extra threaded sectionpast prop will to done too. Must make rudder and install it, the rudder will extend out past the stern.

Tell me! What do I do next?

Is K-3 to be sanded flush, if so, this would cause a broad flat area. is it to then have a 1" strip of fibreglass tape applied?
OR

???

Glad to have a staple gun on hand as it came in handy to close up the chine seams where my clamps could not reach. The staples get removed once the glue dries.

Any suggested filler material along the seams?