No, G-HUBB was another one. As Red Four says, David Martin Couriers operated G-SVHA.
The Merlin was I think nightly from/to Frankfurt. It started as EO111, which became EXT111 when designators went three-letter. I belive It is still running forty years later, albeit to Coventry now, same c/s and operated by a Shed. Once so common in the night sky, there can't be many of them left now.