Draw your plane up in a CAD program, 3D CAD would be especially useful.

I agree CAD is very useful. It might take you 3 months of fooling around to
teach yourself well enough to make it a good tool but in my case I found the
time well spent. It's kind of nice, for example, to be able to drop a
different a different rudder pedal design into the drawing and discover that
the cable will make contact with the control stick at full deflection - before
- you actually build it.

It's also usefull to be able to make an acurate full size print of a part on
your own personal printer. Sometimes it's faster to draw up a simple part in
CAD, print it, and glue it on the material then it is to lay it out in the
conventional maner. This also avoids any distortions due to copy errors if
your plans have "full size" templates.

Your eventual distribution would be a lot cheaper,

IF - you can figure out a way to keep the files encrypted for use by the
purchaser only, and off the Internet........