there was a chap up here in norfolk, owned a pub.......had a merlin engine in the fireplace, (exhausts up the chimney!)....after being primed with many pints (he and the merlin) of a friday night, he could be talked into firing it up....obvoiusly the place was full to the 16th century beams with petrol heads/aeronuts etc etc......don't think he ever needed the flu swept!.....those were the days.....mid 70's....he, and the merlin are long gone and sadly missed