I'm absolutely brand new to this.  What does Williams by Bachmann mean?  Further, I turned up an old Bachmann  engine (ten bucks) at the Deerfield Beach Museum show and the closest I've come to IDing it is "New Heritage Locos from Williams by Bachmann except that mine seems to a model of an earlier version of the engine.  Where can I look for more details on the engine?

Thanks,  Mort