That's interesting... although I don't think it is the correct location, as the buildings/walls look old enough to be in the original film.
But, the idea of a river running alongside the road is very interesting.
Looking at the original film scene it does look as if there may be a dip to the side of the road...

That's exactly what I thought. However I did some further research and it turned out that there used to be trees on both sides between house no. 12 and 18.
In fact a kind lady who lives in Fillé since 1977 and who wrote an article about Chad beeing in Fillé in 2014 said that Rue du Canal used to be the location for the 2nd scene. So I think it is now safe to say that this is the missing location.

Yep - that does indeed look to be the actual location!
Again, would be great to see pictures/map from the area back in the 70's, to see if there were trees both sides of the road.

That would be great. But I think it's nearly unpossible to find pictures from that era on the internet unless you know a photographer from the region, a collector or even someone from the set. I tried my best. However I managed to find two images. #1 is supposed to be from the late 30s and #2 from the 50s

30s

50s

Well, they do look fairly conclusive!
Congratulations - location found.

Location added Google Maps