Hi PS,
This is perhaps more of a lead than an answer, but its a start.
Forgive me if you already know this, however Coventry Climax engines were used in a number of variants beyond their original intended use - the ill-fated Hillman Imp being one of them. This is a link to the "The Imp Site"'s page dealing with engines (there's a page on CC engines), perhaps there's a clue in there -
http://www.imps4ever.info/tech/index.htmlAnd this is the link to the Home page, complete with a contact address if you don't find what you're looking for -
http://www.imps4ever.info/index.htmlArgyll.
