I remember the AA Cessna 421 (G-OBCA) and subsequently their 2 Beech 200's (I think G-KBCA was one of them) and Agusta 109 (G-HBCA?) being based at Blackbushe during the late 80's/90's.
The Cessna 441 was I think G-AUTO but I don't remember seeing that at Blackbushe much.
Prior to that (I think in the 70's) there was a PA23 that they operated, in an all-over Union Jack scheme and a Jet Ranger. These both also lived at Blackbushe from what I remember.