A suggestion if I may: Whenever I take off old covering on a plane built by someone else I make it a point to take some Elmer's Carpenter's Wood Glue (the Exterior version), thin it about 50%, and paint it on all the joints with an inexpensive plastic handle hobby paintbrush. You don't need a lot of glue on the joint - just paint it on quickly and neatly and go on to the next wood joint. When it is dry the glue will have gotten into whatever little cracks and openings that you may not have seen and, because the glue shrinks as it dries, won't really be noticed. Wash out the brush and you can use that again on another project. Go over the framework lightly with your sanding block and you're ready to get on with the covering procedure. Adds peace of mind for a little bit of extra time and effort.

Soft landings.

Joe