Question, additional ground to engine

[V12Bill]

My 46 and 48 Lincolns have a ground cable that goes from the + post to the battery box to the engine. My 39 pickup has a cable from the + post to the firewall and a second cable from the firewall to the engine. Apparently Henry knew about grounding his electrical systems and probably had similar grounds on other cars. It seems that some owners have a "better " way to do things and then run into trouble. On new restorations often ground bases get painted over and a good ground is lost.