Mike
Thanks for your response.
Almost immediately after I posted my question I called some of my research friends in the UK and got quite a bit of information on what was called the Cherwell Jeffris bomb prior to its being assigned the code name "Journey's End". Most interesting to say the least. As a result I have some additional leads to pursue that should prove most interesting.
If you look up Millis Jefferis on Google you should find some good info, including a Wikipedia page on Jefferis that has some tasty bits.
I appreciate your response and taking the time to try and find more info!
Yours in research, with thanks,
AlanG