55023 (L123) is deputising for 51381 of Class 117 three car unit L405, as it takes the Bicester line at Oxford North Junction on 20 July 1990 with the 2C66 17:35 Reading to Bicester Town Network SouthEast service. Obviously some work was required on 51381, so 55023 has been coupled up to L405's 59491 & 51340, to reform a three car set.