I wanted to double head my Flyer passenger train but Flyer wide gauge locomotives have blade type couplers on both ends. So I made and adaptor to hook two locomotives together. I'm sure this has been done before but for anyone thinking about it below are some pictures The adaptor was made from 2 old tab type couplers hooked together so they articulate in the center. I'll paint it black next time I have that color in my airbrush and it won't be visible at all.
Pictures and a video of the train are in Chris Lonero's Tinplate photos post.