The only reference I can find to the dates of the role of the R/O in BEA is that they were phased out finally in 1962. This would have covered the service years of the Elizabethan as they were sold around 1958. I can certainly remember them being on the Viscount 701 in the late 50s/early 60s when my father flew them, they were gone by the time he transferred to the 802.