Orange tissue and clear dope might look more consistent in color and would be lighter.
Since it is a rocket airplane with a big hole in the arse end - you could fixture all your formers to a central rod or tube for assembly. But fuse halves is cool too.
Re your tail surfaces - built up or sheet? If sheet, maybe narrow 1/64" ply doubler strips up to the stab (i.e. not the full fin chord width - too heavy) plus small tristock fillets.
Cool project.. did I say that already?