Yes, the prototype was mostly tested with the Bernard diesel.
This engine was a bit intriguing, firstly because it was the only french diesel ever used on a voiturette ! Then it was a very light unit (24 kilos without oil) and almost the smallest ever seen on a road vehicle (only superseeded by the Yanmar L40 AE 199cc, seen on the first Microcar 50 LD-GLD). But it wasn't really ready made for a small car, as it didn't had any electric starter.
In fact, the only brand who has used it a bit on a few cars was Erad. They had really tried about every engine that was available in these days, Sachs, Motobecane, BCB, Farymann, Lister-Petter...
Daniel Renard built about 130 Capucine 4/50 D with the Bernard. But again it wasn't well suited for a road car, and a bit underpowered as well.
The funny thing is that Bernard Moteurs bought out Erad later, in 1994.
But for the Noval, it should have been one of the first diesel voiturette available on the market. Sadly (or not !
), Noval stopped everything very early, and the car wasn't even typed approval by the Mines.