Here's a quick & rough attempt (if I've got it right...) with Google "My Maps", which I just discovered...lets you draw lines on top of google maps! No computer graphics skills needed..
Interactive version: luxembourg-lyon-laon-leiden - Google My Maps
View attachment 60185
That's brilliant. Thank you for doing this. It is interesting that the lines produce an irregular diamond shape, which in three dimensions would be a tetrahedron. It also seems to be pointing towards the south of France. I bet if you extended the line of the arrow point formed at Lyon down that it will run through or near to Rennes-le-Chateau. When I first read this excerpt from the transcripts, I thought Clover Dale might be linked to the valley of that same name in Yorkshire, which might then have linked it to the Philosophers of Dancar clue. However, I now suspect that the reference may relate to the 'Golden Valley' found in the name of the Heiron du Val d’Or ("Of the Valley of Gold" or "Sanctuary of the Golden Valley"), which may be located in the Rennes-le-Chateau area. For example Le Bézu, which is close to Rennes-le-Chateau (both are in the District of Aude), is linked with ancient gold mines. Curiously, if you play around with the name Bézu you get Zubé, which is not far removed from "Zuber", which formed another clue from the C's that I linked with a set of pyramids on or near the 29th parallel. Hence, extend the line and see what you come up with.