The track on the section of the Cotswold Line between Charlbury and Ascott-under-Wychwood was still laid with vintage bullhead rails until early 1986. During April it was relaid with continuous welded flat bottom track, bringing it up to current mainline standards. With evidence of the weekend engineering possession on the left, L425 (51405, 59515 & 51363) passes over the newly installed track at Chilson on 26 April 1986 with the 08:08 Oxford to Moreton-in-Marsh service.