I, too suggest intalling the tail first. it will assure better alignment and a neater covering job.

A good way to cover the tail is to first cut a strip of covering about 1 inch wide and install it in the corners. For example: on the bottom, attach the strip in the joint, half to the stab and half to the fuse. Then the larger pieces can be installed flat with the ends butted into the corner. The seam is just about invisible. The same technique can be used on the fillet on top between the stab and fin. It comes out very neat and tight with no lifting of covering in the corners when it is shrunk.