Now select those three curves, and go to edit curves/offset curve. You must look at curves from orthographic view (use compass). Set mode to active view.

Then select all curves and go to edit curves/cut curve. This will cut curves at their intersection points.

Delete small parts.

Create one curve to close inner surface of the blade. This curve should have same number of CV's as edge of a blade.

Select inner curves and press SHIFT+Q. You will be in component mode, then grab CV's and move them.

Then go to edit curves/rebuild curves option box and use this settings. If you have pair of curves with different number of spans (you can see that in attribute editor), specify number in rebuild options to get desired number of spans and cv's for curves.

Select inner and outer curve like this.

Go to surfaces/loft. This will create surface between two curves. Repeat this for all curves.

Then select four inner curves.

Go to surfaces/boundary. This will create surface between four curves.

Duplicate surfaces across Z plane.

Then create two more curves on the handle.

Go to surfaces/revolve option box. For axis choose Y.