Yes, Cov Eagle did make their own semi unit engine for a few years in the early thirties but soon gave them away and stuck to Villiers. Yours is Cov Eagles own unit with the original Lucas electrics. As yours has the tin primary chaincase and C/E had introduced their fully enclosed aluminium primary chain case by 1934 I'd say 1932 was correct.
As it happens Radco, the author of 'The Vintage Motorcyclist's Workshop' restored one of these and there is a double page spread photo of the result plus a little bit of info on pages 180-181 of his book.
Radco used to write a regular column in the VMCC Club Journal and he wrote at least one column if not more on restoring the little Cov Eagle and went in to some detail about the engine. His book is basically a collection of all his columns and was published in 1986 so if you want to know as much as anyone does about this particular model Coventry Eagle I'd suggest looking through back copies of the VMCC Journal from 1986 backwards until you come to it.
Finally, I see your bike is registered HY 5929 and the Radco bike is registered HY 6568 so they possibly sold by the same dealer.
Cheers,