I can't emphasize how much important it's to have the stab parallel to the wings ...
So in order to position the main tube of the flying stab, I'm not using a carbon tube, but an arrow I bought in LA when I was flying a Jekyll with Greg OKKERT and Warren FOX in Mile square Park ....
This arrow is made of carbon outside, and aluminium inside, so perfectly straight.
The alignment from the factory was perfect, so I didn't did any adjustment.
Just gluing the main tube with CA, then I positioned both stabs to check for the carbon tubes length , and the clearance I want between the stabs and the fuselage.
Locating the hard wood in the stab is easy. After marking the center, I drilled 1,8 mm holes in the right stab and carbons tubes.