Building a Magneto

I save all these FM magneto parts, then I build my own.  I've never bought one all complete (kinda expensive).  The original Fairbanks-Morse parts are good - and I like anything NOS (still-in-the-box).  I have a great source for charging magnets, checking coils, checking condensers, etc. and troubleshooting.  I have a magneto firing the plugs in about everything I run.  Most times on a "magneto fired" engine when it won't start, the first thing that gets blamed is the magneto . . . since it's the most misunderstood. 
Hey, it ain't Old Sparky's fault !