If these prior suggestions don't help, contact a drafting supply company. If you have an architect's supply house nearby (or check the web), you should be able to get plenty of things we quilters use: grid paper in larger sizes for drafting blocks; template plastic; accurate plexiglass triangles/squares/rulers; compasses; rulers; you name it! That's where I get my very large sheets of grid paper for accurate drafting of my own blocks/templates. Then I only need to use the template plastic if I can't rotary cut what I need.
HTH,
Odessa