Its a noble effort, but there's no holds barred. Part of the spoiler contains this....
"In total around seven

and five ? models were made between 1969 and 1980. These

are extremely fast with the ? model able to reach 140mph!
Its going to be difficult without using the clue.....unless you are familiar with the story, or you follow the trail of the FCF coincidence
So your last whatsthisthen? within a day or so an Ashley appears on oldclassiccar.co.uk's car of the day today
Citro Jim has a cycle ride to Biggleswade to supply a picture of the day for the FCF today, and where are/were your Berkeley three wheelers made.................yes Biggleswade
..and if you follow whatsthisthen? there is another similar recent coincidence which will lead you to the answer!
Easier to go through the spoiler and google some of the wordy bits
REgards Neil