Andrewmc-
How about this for templates? I placed the cut out ribs onto a photocopier (lucky to have an office at home) . End up with a 1:1 print, I could even scan at 1:1 and email.
OK these are the GP ribs not the Goldberg but easier to make than card templates. paste onto balsa sheet and sand down to the edge.
I always thought the copier put the copies out just a bit smaller than the originals. How well do the parts line up?