Wasn't there a Heron operated by British Nuclear Fuels or some such organisation?
Marconi had a Piaggio P.166 for quite a while, remember seeing it over South Croydon one day many years ago - now in the Science Museum collection at Wroughton.
Another corporate twin once seen beating up Purley's "Volkswagen Building" just a stone's throw from where I type this was VW's Islander - used for parts distribution I think!