Yes this is like the earth grounding kit I fitted to my Jeep many years ago, just to dress it up. Along with all the required filters and suppression parts that Lynn mentioned.
https://www.mvspares.com/WWII-JEEP-P...iijeep-418.htm
In line suppressors were fitted in the HT leads of motorcycles which was detrimental to their use, as magnetos don't work as well through a suppressor.
Ron