I would definitely recommend covering the whole thing all the way to the firewall. Otherwise you would have to glass the front and paint. A finished fabric covering like Solartex (Worldtex, Colortex) would be easy, and really looks better than plastic on this bird.

I agree with Les that this plane begs for a 4 stroke as do most biplanes (this is a nice project for a 91 4 stroke, or the Saito 100, or even an old used 1.20 that you could find fairly cheap). A 4 stroke lets you swing a larger prop which helps the prop clear that wide nose. I suspect you could fly it on a 2 stroke, but it would be harder for me to pick one. I think a 60 would be too small (at least for the way I like to fly). Maybe a 90?

Les also brought up a good point about lightening the tail. If you can, I'd recommend lightening the tail as much as possible before covering. An ounce saved in the tail, probably equals 5 or 6 ounces saved in nose weight on this plane.

As for the hinges, I thought you meant they had a pin through the hinge line. If I'm reading you right someone built the plane then permanently hinged the control surfaces before covering. If this is the case, I'd recommend cutting the hinges, covering then re-hinging the surfaces. It will save you time in the long run. You could use Robart Hinge points, hinge next to the existing hinges, or remove the existing hinges and re-hinge in the same location.

I also recommend the Robart Struts for this plane. Really cool. My photos show the Robart plastic strut covers, but I later added the real stuts to my plane also.