Have you looked at the steam drawbar closely? There's mounts on both sides that have to be accommodated, it'll be considerable work.
Why not just use something like the Miniatronics 2 Pin Micro Mini Connector to bring the coupler over? It's really tiny and will be a bunch easier to install and live with than the blasted "wireless" drawbar! If you wanted lights, they also have a 4-pin model.