Hi Gary,
I suggest you make your aft fuselage a full cone
shape by closing the vertical tail opening.
And I agree to use glass for this
work.
I (and several others) found this was needed
after cracks formed near the top of the fuselage at the tail.
It's a bugger of a place to work. It would be
easier with the plane inverted.
I'll send some pics if you need them.
Mark Ravinski
360 1470 hrs