Arrrrr!!! We agree with The Buccaneer. Many of the magnetos used by Neptune were made by Eisemann. Visit oldcroak.com for Eisemann flywheel magneto information if this is what you have. There should be a make and model number on the backing plate. Eisemann went away sometime in the late 1940-1950’s. If there is contact material left on the points by all means polish and reuse them. Files are much too coarse. Use a fine sharpening stone or Cratex stick and get them smooth. They will stay clean longer Sourcing new ones will be dodgy. Retrofitting will be a challenge as it may affect edge gap (timing of the opening of the points vis a vis the position of the rotating magnet to get the biggest bang). A far bigger problem with these old eggbeaters may be the condenser. Have someone test it for electrical leakage with an actual automotive condenser tester designed to do so. Use almost any automotive condenser. Hope this helps!
