Hello Trevor
I believe the boot handle is a Rover P4 door handle
I put a list of what I call interchangeable spares in the Greyhound section of the Model Directory which mentions the boot handle, if anyone has any additions to this list please let me know. there are also copies of Road Tests and other articles which might be useful
I don't think we have been in touch and I don't remember seeing your name as a new Greyhound owner but I'd be grateful if you cold let me know which car you have and perhaps send pictures for the Register
Best wishes and Good Luck
John
johngoose1@icloud.com