Conducting Power on a Scratch Built Chassis

Let me try and clear some of this up. I've had little experience with electronics themselves and thought it would be impossible for me to build a working TOMY/TM style chassis from scratch (as opposed to a replacement body for an existing one). Watching numerous repair and restoration videos and paying attention to that conductive piece made me realise I have aluminium foil, which made me consider taking advantage of the way these units are powered. Because I have more complete rolling stock than unused parts, the components will have to be swapped out easily and allow each custom chassis (and shell) to be reusable. As stated above, I already found the answer to my question since the foil did power one of the motors and will only have to be incorporated into a (well built) custom frame.