Milt, The aircraft were WF381 "41" and WL681 "11". ETPS used several machines over the years including the prototype VX828 when it was dismantled circa 1962 at Farnborough.
WF381 crashed 4 miles North of Tangmere on a training flight with ETPS 19.10.59. WL681 ended up with Shorts at West Malling.