The article says :
"The car that the brothers designed and produced was named the Everson Cherub as a nod of respect to their father, Ern, who had built three sports cars and three aeroplanes while they were growing up. All the sports cars Ern had called the Everson Cherub to denote their minuscule size and lightness, hence the brother’s choice of name. The originals were powered with 250cc motors yet could do 120kmh, an impressive speed in those days."
All Eversons have been mentioned so far anyway, apart from Darren Everson but he only provided the pictures and information for the article.
On a side note, there is no evidence that the puzzle car was Mini-based. The Moke-like Cherubs were Mini-based indeed, but nothing says this sports car was too.