It looks as if an incredibly beautiful and perfectly detailed model of the cannon was produced. I would give my right arm to get a hold of a copy of the plans this person was able to produce.
It was over 5 years ago you started this thread. I wonder what dimensional information you ever came up with and how the project turned out?
My grandfather was a lieutenant with Battery C, 6th Field Artillery and was involved in the firing of the first American shots of the war from their French 75s (not M1897s). In his honor, I am right now starting on a similar project, except my French 75mm will be somewhere between 1:10 and 1:5 scale. I don't plan on it being capable of actual firing, but hope to have many of the mechanisms operable.
Like you, I want to start by making CAD drawings from the annotated drawings. First of the full scale weapon, then of my design for the scale model. Then finally I can begin the lathe and mill work. And the carpentry with the wooden wheels.
I have collected quite a bit of info and photographs from the internet, but nothing with the sort of detail needed to build an accurate model. I can share this reference material with you if you would like.Â
I also started some basic drawings, but without access to an actual canon it was very difficult and I put the project on hold to build a steam traction engine instead. I would be very interested in seeing your drawings for the French 75 canon.Â