Built by Hunslet in 1958 for Stewarts and Lloyds of Buckminster, Rutland, Juno worked in the company's ironstone quarries until 1968. It was one of the few 'Austerities' to work on the ironstone system of the Midlands.

On 31st May 1969 Juno was delivered to Quainton having being purchased by the Ivatt Trust. During the first years of the Quainton Railway Centre, Juno was a valuable asset, working alongside Sir Thomas in the downyard.  Juno and Sir Thomas then bore the brunt of services for the rest of 1971 and throughout the following years.  In June 1972 Juno was moved from the Downyard to the upyard. Now the engine can be found in store in the up yard shed, waiting for retubing and the day when it can take up passenger duties once again.