Solved -PJ568- Lorenzo Gradé's 6 cilindros 7hp from 1927

[Paul Jaray]

Correct!
The easy part was that if you google the right words the car can be found online, the hard part was that it's not mentioned in any book (or at least I didn't find it so far)!
Point for you!

[targhediferro]

Actually I searched in every site and forum I know about spanish (and not only spanish) cars, without any result...than I try with a normal Google research with the only clues I had, "automovil seis cilindros 1924-1925-1926-1927-1928 espana", and I found the site where it's pictured.  It seems that Mr.Gradè studied and perhaps realized an engine with a very strange cylinders-disposition, and a particular carburator too.   Thank you for the Lock, without it I would have probably overcame by quicker quizzer or I would have quit my research before finding it.

[Paul Jaray]

It's true...if you find the right key words you find the source of the pic and since you found the crucial one (it was a Six from Spain) it was fair to give you the chanche to complete it.
Here are some patents of Mr Gradé: