Andy,
I was otherwise engaged with Vultee Vengeances at that time, but HB301 would almost certainly have been a Mark IV modified as a target tug. I saw one flying over Ormskirk (Lancs) as late as summer ’46). Think the Navy had them at Burscough (?) – not far away. HB301 must have been almost the first to come over, for the series started with HB300 (Peter C. Smith: “Vengeance” 1986).
I Post on “PPRuNe > Military Aircrew > Gaining a RAF Pilots Brevet in WW2” (as Danny42C), if it is of any interest.
Danny,