The DSC news story on Pescarolo the other day they seemed to be using the phrase "customer chassis" as a plural, and as other have said something like a KWM chassis with a Judd engine wouldn't be 'surprising'.
I'll wager my £1 upon a Pesca chassis with a works backed Nissan Engine.
Finally, thankfully someone else posted the Endurance Info link first, my schoolboy French has translated Jeudi as 'Wednesday'. No wonder I was bottom of the class.