G'day Rudi,
Go back to page 27, I posted a method that I used to assemble the tailplanes.
I mentioned back then I was not convinced that a modification is needed. I still believe that to be the case. Correct length and correctly fitted spars ensuring epoxy is where it should be will provide more than adequate strength in the assembly.
DON' T use quick drying epoxies. Take your time, I can assure you it WILL be worth it...........
Cheers
Ken