This would be Ashton Mk2 (and the second airframe) WB491 which was converted by Napier and Son in 1954 as a universal engine test-bed for National Gas Turbine Establishment. It flew with a RR Avon in a ventral pod but in 1955 the pod was replaced by a RR Conway for the Boeing 707-420.
I think what is seen at 26s is the Ashton (look at the tail) and there is just some equipment next to it that looks like propellers.