Just picked up a Marx 1666 locomotive, and while removing the non-running motor, to my surprise I found the same primitive ‘chugging’ mechanism found in some of the cheaper 490 locomotives using a side rod activated brass strip as the ‘chugger’. This looks like a factory installation but have never heard of this mechanism in the 1666s.
So, my question is twofold. did Marx in fact make this variation of the 1666, and if so, how rare would it be? Any information would be greatly appreciated.