I am looking forward to receiving my D5705 from Hattons. It will join my two faithful Hornby Dublo models.
Having grown up in Western Australia where there were 48 locomotives with the same engine as the Co-Bo, I have a special affinity for their UK relatives.
What sound recording are people using? Listening to the sound on Savoyard's posting, the engine beat seems too regular and smooth when compared with my recollections of the Crossley engine in the X and XA class diesels of the Western Australian Government Railways. Its more like a four stroke to my ears.
The Crossley V8 configuration engine was two stroke and had a deep uneven "rum rum rum rum" beat at idle and when powering up the uneven beat from the two banks of cylinders was very noticeable. Listen to a Triumph Stag or P6 Rover 3500 motor car with a slightly throaty exhaust and the sound is not dissimilar. Drive off in a Stag and gently increase the revs as if notching up with set speeds and the sound resemblance is very strong. My mate who has a Stag does it often when wanting to wallow in the nostalgia of the Metro-Vicks. A fantastic sound and very loud, especially in their early days when the exhaust silencers were rudimentary. On a still night in the country a train could be heard coming from miles away, for 20 minutes or more; increasing revs to climb up undulations and going back to idle when coasting down the other side.
As for smoke, a good Crossley could emit black smoke so well under full power that the rear of the train couldn't be seen from the loco. When used on suburban passenger trains in Perth and after sititng at idle at the turn around points, oil would build up in the muffler and a trail of white smoke would billow around the train as the oil burned off when the muffler heated.
I await the postman and chance to swap the wires around. It will be a great day when D5705's engine return to life too.