You could take the parts in and show them what you are tring to do and let them measure everything, and make their own drawings,or you can draw the plans yourself.

DIY
 Basic type of matieral:  Cold Roll steel... this is the kind steel goes well with magnetic applications.

  You will need a drawing: Just draw the basic shape and make look kinda close to the finished product.

  Now the dimensions: If your are in the usa this should be in thousands of an inch.
   If any part of the world, Dimensions will noted in Millimeters.
    To measure this a set of dial calipers will work.

  As an example for an electric type of Alt:

   Stator inside diameter is   3.000 +- .010
   Rotor outside diameter is   2.000  +-.010
This would give you a difference of 1.000  that is one inch, you now have a 2 inch
rotor in a 3inch Stator hole...this leaves 1/2 inch per side to put magnets and leave an air gap.
   You can make your on bluprint drawing and take it with you......Hope this might help some.                Frankenbuger

     I suppose a one off could be done on a lathe but you have to have something to start with. Then those laminations would have a rotor die and a stator die (several $1000 each) made to cut rotor and stator slots. Another large die might be needed to make the hole in the center of the rotor for a shaft.

Magnet manufacturers have been extremely helpful and have manged to keep the prices in the reasonable range (Neodymium). Very good considering the turbine is shaftless; an integral part of the rotor, and has the bar magnets mounted directly to it. The turbine itself is suspended in a magnetic flux, the principle called levitation, so as to produce a frictionless magnetic bearing.

The Stator must fit over a 2" PVC Pipe as the turbine mounts inside one to produce power from rising hot air gasses. It can be used in ventilating the attic in your home while generating electricity, or inside a solar chimney.