I started with a set of blue prints of a Plus 8 that someone posted on the
emog discussion group a few years ago.
In looking at the wheels available in the Lee Valley catalogue the only ones
that had the correct looking thickness to diameter ratio were the 2 1/2"
diameter ones, so that set the scale.
I cut out the four views in the blueprint into separate pictures, then
scaled up the side view until the printed copy had wheels 2 1/2" across.
Then I scaled up the rest of the views the same amount. Using these
diagrams as guides I made three templates from some scrap acrylic. Template
"A" is the wing/body line, "B" is the profile of the top of the body, but at
the front it stops above the headlights, "C" is the side of the body where
it meets the wings. The templates are drawn on a 1/4" grid.
Note that the templates do no exactly fit the blueprints. After cutting a
set of templates from the blueprints I felt that the front wings were too
thin and, therefore; would be too delicate made of wood. I fattened them up
to 1/4" thick on my printout of the blueprints and then drew and cut a new
chassis template to keep a 1/8" of wood around the wheel well. This pushes
the nose of the car forward a little so the top profile template was also
modified. But for the side template I just pushed it forward 3/16" when
using it. This thins the rear deck a little, if you like, you can stretch
the nose of the side template forward keeping the same width at the front
and having a shallower taper to the bonnet.