I've been fettling loco's recently, stripping down motors, adding pickups to wheels and installing DCC chips. Working with my mate John we have turned several locos from the 1970s and 1980s into good runners again.
I'd upgraded a couple of Lima Class 66 previously, including a whole motor replacement, but they still improved their running after a fettle. The improvement was big enough that to my surprise, the Freightliner 66 could pull my intermodal train.
Knowing that the real thing passes my house around 6 o'clock each evening, I hatched a plan to film them both runnnig at the same time.