If your Mehano runs that well; you may get away with hardwiring the two together. These things have street prices that are so low that it does not hurt to buy a pair and hardwire them together. If anyone has an old one with a fried motor; if you remove the motor; the contact wipers will remain. You can run jumpers from the Bachmann to the wipers on the depowered locomotive.
There is also the choice of a 'live' car.
While some may consider the Kato North American caboose a bit pricey for this; you can find many of the 'live' Kato and Micro-Ace JNR brakemen's vans at shows for twelve or ten dollars (or even less). One of those bashed into an industrial hack looks more convincing with the MDT; anyhow. Some of them have tool compartments and other such things that you might expect to find on an industrial hack.
There is also the choice of a 'live' car.
While some may consider the Kato North American caboose a bit pricey for this; you can find many of the 'live' Kato and Micro-Ace JNR brakemen's vans at shows for twelve or ten dollars (or even less). One of those bashed into an industrial hack looks more convincing with the MDT; anyhow. Some of them have tool compartments and other such things that you might expect to find on an industrial hack.