No.4 was the second of the Keef type K12 locos, and the first to be supplied with full bodywork and a cab. It was delivered on 6 November 1979 to Country Kitchen Foods Ltd, Wilmslow. This was a peat works on the outskirts of the town, which operated under a number of different company names. In company with two Listers, the loco spent its entire working life at Wilmslow, including a moment of fame when “Lindow Man”, the remains of an Iron Age man, were discovered in 1984. He is now on display at the British Museum.
In 2020, all of the remaining railway equipment at Wilmslow – three locos (see also numbers 5 and 55), a number of wagons and some track – was recovered back to Apedale thanks to the support Croghan Peat, the current operator of the site. No.4 arrived at Apedale on 25 June 2020.