
Some questions have been asked about the Leaf coupler used by Johannes (here). I've discussed this with my colleagues in Amsterdam and can confirm they are selling a new version of the coupler ("puck") to end users

The puck costs €250 and uses the exact DIN norm of the Leaf spline. Included in this price is the drilling of a bespoke bolt pattern to match the flywheel you are using. Some bolt patterns are already on file but if you have something exotic they just need a dimensioned drawing of the bolt pattern or you can send them a flywheel and they will do it for you.
Blank pucks are also available for €225 if you want to drill your own flywheel holes

I can also confirm that New Electric can supply adaptor plates for mounting motors to gearboxes. They have many motors and gearboxes on file but if not they just need a dimensioned drawing.
Attached are some photos of the puck and adaptor plate for the Siemens motor.
If you need more information please contact New Electric Conversions (website). Here's the email address info@n-e-c.nl