Nice looking job. I completed the GP Extra 300s .60 size and yours seems very similar.

Regarding the pictures that you have posted of the vertical fin and rudder - suggest that you double check the construction ofthe trailing edge of the fin as well as the leading edge of the rudder before you go much further. I suspect that those pieces of balsa should extend to the bottom of the fuselage as one piece.

Love seeing the pictures.

Charles