Originally Posted by
possel
Possibly there was an Argonaut as well, but an armoured floor was fitted by the RAF to one of the Queen's Flight Vikings VL232 for a royal tour in South Africa. According to p.19 of "The Eagle Years" by David Hedges, Eagle Airways subsequently bought it as G-APAT and considered it "down on performance" until they found the reason!
There is a picture, in Brian Trubshaws book "Test Pilot", of Royal Flight Viking VL247 at Cape Town in 1947 (probably at Ysterplaat or Wingfield). The Viking visible just behind is 246. Apparently four Vikings were taken on the tour.